The same way that factoring a number is different from multiplying two factors. In general, it is much easier to multiply two factors together, than to find factors that give a certain product.
a²-b²
Use the "F-O-I-L" Method when multiplying two binomials. F-O-I-L stands for First, Outer, Inner, Last. Multiply the first terms together, then the outer terms, the inner terms, and the last terms.
A product is the answer when you multiply two or more numbers. 5x3=15 so 15 is the product. 21x2x1=42 so 42 is the product.
A harder version of algebra 1
A binomial has two terms, while a trinomial has 3 terms. So both terms of the binomial will multiply each term of the trinomial (distribution property). After the multiplication you'll have 6 terms. Look for like terms, if there are, combine them.
It is only not needed if you know of another method. If FOIL is the only way you know to multiply two binomials, then it is definitely needed.
multiply the 1st term with whole bracket and the 2nd term with whole bracket
To multiply two binomials you use FOIL (first, outer, inner, last): (y-9)(y+10)=y*y+10y-9y-9*10=y2+y-90
Square of BinomialsSquare of MultinomialsTwo Binomials with Like TermsSum and Difference of Two NumbersCube of BinomialsBinomial Theorem
==UsesAdding integers=== '''Algebra tiles''' can be used for adding [[integers]].Kitts, N: "Using Homemade Algebra Tiles to Develop Algebra and Prealgebra Concepts", page 463. MATHEMATICS TEACHER, 2000. To demonstrate this ability you can consider the problem 2+3=?. In order to solve this problem using '''algebra tiles''' a person would group two of the positive unit tiles together and then group three of the positive unit tiles together to represent separately 2 and 3. In order to represent 2+3 the person would then combine their two groups together. Once this step is complete the person can then count that together there are 5 unit tiles, so 2+3=5. Since adding a number with the negative of that number gives you zero, for instance -2+2=0, adding a negative unit tile and a positive unit tile will also give you [[zero]]. When you add a positive tile and a negative tile it is known as the zero pair. In order to show that any [[integer]] plus its negative is [[zero]] a person can physically represent this concept through '''algebra tiles'''. Let us take the example used earlier where -2+2=0. A person would fist lay out two negative unit tiles and then two positive unit tiles, which would then be combined into two sets of zero pairs. These two sets of zero pairs would then be equal to [[zero]].[http://www.phschool.com/professional_development/teaching_tools/pdf/using_algebra_tiles.pdf] Understanding zero pairs allows you to also add positive and negative integers that are not equal. An example of this would be -7+4=?, where you would group seven negative unit tiles together and then four positive unit tiles together and then combine them. Before you count the number of tiles that you now have you would have to create zero pairs and then remove them from you final answer. In this example you would have four zero pairs which would remove all of the positive unit tiles and you would be left with three negative unit tiles, so -7+4=-3. ===Subtracting integers=== '''Algebra tiles''' can also be used for subtracting [[integers]]. A person can take a problem such as 6-3=? and begin with a group of six unit tiles and then take three away to leave you with three left over, so then 6-3=3. '''Algebra tiles''' can also be used to solve problems like -4-(-2)=?. First you would start off with four negative unit tiles and then take away two negative unit tiles to leave you with two negative unit tiles. Therefore -4-(-2)=-2, which is also the same answer you would get if you had the problem -4+2. Being able to relate these two problems and why they get the same answer is important because it shows that -(-2)=2. Another way in which '''algebra tiles''' can be used for [[integer]] [[subtraction]] can be seen through looking at problems where you subtract a positive [[integer]] from a smaller positive [[integer]], like 5-8. Here you would begin with five positive unit tiles and then you would add zero pairs to the five positive unit tiles until there were eight positive unit tiles in front of you. Adding the zero pairs will not change the value of the original five positive unit tiles you originally had. You would then remove the eight positive unit tiles and count the number of negative unit tiles left. This number of negative unit tiles would then be your answer, which would be -3.[http://www.phschool.com/professional_development/teaching_tools/pdf/using_algebra_tiles.pdf] ===Multiplication of integers=== [[Multiplication]] of [[integers]] with '''algebra tiles''' is performed through forming a rectangle with the tiles. The [[length]] and [[width]] of your rectangle would be your two [[factors]] and then the total number of tiles in the rectangle would be the answer to your [[multiplication]] problem. For instance in order to determine 3×4 you would take three positive unit tiles to represent three rows in the rectangle and then there would be four positive unit tiles to represent the columns in the rectangle. This would lead to having a rectangle with four columns of three positive unit tiles, which represents 3×4. Now you can count the number of unit tiles in the rectangle, which will equal 12. ===Modeling and simplifying algebraic expressions=== Modeling algebraic expressions with '''algebra tiles''' is very similar to modeling [[addition]] and [[subtraction]] of integers using '''algebra tiles'''. In an expression such as 5x-3 you would group five positive x tiles together and then three negative unit tiles together to represent this algebraic expression. Along with modeling these expressions, '''algebra tiles''' can also be used to simplify algebraic expressions. For instance, if you have 4x+5-2x-3 you can combine the positive and negative x tiles and unit tiles to form zero pairs to leave you with the expression 2x+2. Since the tiles are laid out right in front of you it is easy to combine the like terms, or the terms that represent the same type of tile. [http://www.phschool.com/professional_development/teaching_tools/pdf/using_algebra_tiles.pdf] ===Using the distributive property=== The [[distributive property]] is modeled through the '''algebra tiles''' by demonstrating that a(b+c)=(a×b)+(a×c). You would want to model what is being represented on both sides of the equation separately and determine that they are both equal to each other. If we want to show that 3(x+1)=3x+3 then we would make three sets of one unit tile and one x tile and then combine them together to see if would have 3x+3, which we would.[http://www.regentsprep.org/rEGENTS/math/realnum/Tdistrib.htm] ===Solving linear equations=== Manipulating '''algebra tiles''' can help students solve [[linear equations]]. In order to solve a problem like x-6=2 you would first place one x tile and six negative unit tiles in one group and then two positive unit tiles in another. You would then want to isolate the x tile by adding six positive unit tiles to each group, since whatever you do to one side has to be done to the other or they would not be equal anymore. This would create six zero pairs in the group with the x tile and then there would be eight positive unit tiles in the other group. this would mean that x=8.[http://www.phschool.com/professional_development/teaching_tools/pdf/using_algebra_tiles.pdf] You can also use the [[subtraction]] property of equality to solve your [[linear equation]] with '''algebra tiles'''. If you have the equation x+7=10, then you can add seven negative unit tiles to both sides and create zero pairs, which is the same as subtracting seven. Once the seven unit tiles are subtracted from both sides you find that your answer is x=3.Kitts, N: "Using Homemade Algebra Tiles to Develop Algebra and Prealgebra Concepts", page 464. MATHEMATICS TEACHER, 2000. There are programs online that allow students to create their own [[linear equations]] and manipulate the '''algebra tiles''' to solve the problem. [http://my.hrw.com/math06_07/nsmedia/tools/Algebra_Tiles/Algebra_Tiles.html Solving Linear Equations Program] This video from Teacher Tube also demonstrates how '''algebra tiles''' can be used to solve linear equations. [http://www.teachertube.com/view_video.php?viewkey=7b93931b2e628c6e6244&page=&viewtype=&category= Teacher Tube Solving Equations] ===Multiplying polynomials=== When using '''algebra tiles''' to multiply a [[monomial]] by a [[monomial]] you first set up a rectangle where the [[length]] of the rectangle is the one [[monomial]] and then the [[width]] of the rectangle is the other [[monomial]], similar to when you multiply [[integers]] using '''algebra tiles'''. Once the sides of the rectangle are represented by the '''algebra tiles''' you would then try to figure out which '''algebra tiles''' would fill in the rectangle. For instance, if you had x×x the only '''algebra tile''' that would complete the rectangle would be x2, which is the answer. [[Multiplication]] of [[binomials]] is similar to [[multiplication]] of [[monomials]] when using the '''algebra tiles''' . Multiplication of [[binomials]] can also be thought of as creating a rectangle where the [[factors]] are the [[length]] and [[width]].Stein, M: Implementing Standards-Based Mathematics Instruction", page 98. Teachers College Press, 2000. Like with the [[monomials]], you set up the sides of the rectangle to be the [[factors]] and then you fill in the rectangle with the '''algebra tiles'''. Stein, M: Implementing Standards-Based Mathematics Instruction", page 106. Teachers College Press, 2000. This method of using '''algebra tiles''' to multiply [[polynomials]] is known as the area modelLarson R: "Algebra 1", page 516. McDougal Littell, 1998. and it can also be applied to multiplying [[monomials]] and [[binomials]] with each other. An example of multiplying [[binomials]] is (2x+1)×(x+2) and the first step you would take is set up two positive x tiles and one positive unit tile to represent the [[length]] of a rectangle and then you would take one positive x tile and two positive unit tiles to represent the [[width]]. These two lines of tiles would create a space that looks like a rectangle which can be filled in with certain tiles. In the case of this example the rectangle would be composed of two positive x2 tiles, five positive x tiles, and two positive unit tiles. So the solution is 2x2+5x+2. ===Factoring=== In order to factor using '''algebra tiles''' you start out with a set of tiles that you combine into a rectangle, this may require the use of adding zero pairs in order to make the rectangular shape. An example would be where you are given one positive x2 tile, three positive x tiles, and two positive unit tiles. You form the rectangle by having the x2 tile in the upper right corner, then you have two x tiles on the right side of the x2 tile, one x tile underneath the x2 tile, and two unit tiles are in the bottom right corner. By placing the '''algebra tiles''' to the sides of this rectangle we can determine that we need one positive x tile and one positive unit tile for the [[length]]and then one positive x tile and two positive unit tiles for the [[width]]. This means that the two [[factors]] are x+1 and x+2. Kitts, N: "Using Homemade Algebra Tiles to Develop Algebra and Prealgebra Concepts", page 464. MATHEMATICS TEACHER, 2000. In a sense this is the reverse of the procedure for multiplying [[polynomials]]. ===Completing the square=== The process of [[completing the square]] can be accomplished using '''algebra tiles''' by placing your x2 tiles and x tiles into a square. You will not be able to completely create the square because there will be a smaller square missing from your larger square that you made from the tiles you were given, which will be filled in by the unit tiles. In order to [[complete the square]] you would determine how many unit tiles would be needed to fill in the missing square. In order to [[complete the square]] of x2+6x you start off with one positive x2 tile and six positive x tiles. You place the x2 tile in the upper left corner and then you place three positive x tiles to the right of the x2 tile and three positive unit x tiles under the x2 tile. In order to fill in the square we need nine positive unit tiles. we have now created x2+6x+9, which can be factored into (x+3)(x+3).[http://www.regentsprep.org/Regents/math/algtrig/ATE12/completesq.htm]
Depends on the kind of binomials. Case 1: If both binomials have different terms, then use the distribution property. Each term of one binomial will multiply both terms of the other binomial. After distribution, combine like terms, and it's done. Case 2: If both binomials have exactly the same terms, then work as in the 1st case, or use the formula for suaring a binomial, (a ± b)2 = a2 ± 2ab + b2. Case 3: If both binomials have terms that only differ in sign, then work as in the 1st case, or use the formula for the sum and the difference of the two terms, (a - b)(a + b) = a2 - b2.
-15.299999999999999
The same way that factoring a number is different from multiplying two factors. In general, it is much easier to multiply two factors together, than to find factors that give a certain product.
a²-b²
The ones that are the sum or the difference of two terms.
Use the "F-O-I-L" Method when multiplying two binomials. F-O-I-L stands for First, Outer, Inner, Last. Multiply the first terms together, then the outer terms, the inner terms, and the last terms.