20 = 1Consider what is the value of 2a ÷ 2a? Any number divided by itself is 1. Thus:2a ÷ 2a = 1The law of indices says that when dividing, they are subtracted, for example:25 ÷ 22 = (2 x 2 x 2 x 2 x 2) ÷ (2 x 2) = 2 x 2 x 2 = 23 = 25-2So 2a ÷ 2a is (also):2a ÷ 2a = 2a-a = 20Since any number subtracted from itself is 0 (= a - a). This must have the same value as before, thus:20 = 1The 2 above can be replaced by any number x which means that any number to the power 0 is 1:x0 = 1
x + 2a
The quadratic formula originated from the concept of completing the square. let's take ax2 + bx + c = 0. To complete the square, solve for x. Subtract c. ax2 + bx = -c. Then divide by a [notice- if there is no a value, then a=1]. x2 + bx/a = -c/a. Add (b/2a)2 to both sides. x2 + bx/a + b2/4a2 = -c/a + b2/4a2 Factor/Reformat. (x + b/2a)2 = (b2-4ac) / 4a2 (x + b/2a)2 = [(b2-4ac) / 2a]2 Square-root both sides. x + b/2a = ± √(b2-4ac) / 2a Subtract b/2a. x = -b/2a ± √(b2-4ac) / 2a Combine terms. x = [-b ± √(b2-4ac)] / 2a
We will use a tool called a quadratic formula. First, I will prove it. For all degree two function f(x) = ax^2 + bx + c where a, b, c are constants, claim the roots are -b +/- sqrt(b^2 - 4ac))/2a IF a is not 0 and b^2 - 4ac >= 0. Proof. Suppose the conditions are satisfied, finding the roots of the function is the same as solving the following ax^2 + bx + c = 0 we will simplify, since a != 0 a(x^2 + (b/a)x) + c = 0 we will do a trick, a trick that you see once, you will never forget, we add then subtract the same thing a(x^2 + (b/a)x + b^2/(4a^2) - b^2/(4a^2)) + c = 0 Now notice b/a = 2 . b/2a, we will do that, also, we will take -b^2/(4a^2) out, notice, b^2/4a^2 = (b/2a)^2 Then we get a (-b^2/(4a^2)) + a( x^2 + 2 (b/2a)x + (b/2a)^2) + c = 0 we use the complete square identity -b^2/(4a) + a(x + b/2a)^2 + c = 0 Isolate x a(x + b/2a)^2 = -c + b^2/4a = (-4ac + b^2)/4a (x + b/2a)^2 = (b^2 - 4ac)/(4a^2) (x + b/2a) = +/- sqrt (b^2 - 4ac) / 2a x = +/- sqrt (b^2 - 4ac) / 2a - b/2a x = -b +/- sqrt(b^2 - 4ac))/2a Q.E.D Now apply the quadratic formula to your question: x^2 + 8x + 25. First check if a = 0, a = 1 != 0, pass. Now check if b^2 - 4ac is non-negative. 8^2 - 4 x 1 x 25 = 64 - 100 = - 36 < 0. Done, this function have no roots.
A quadratic equation is an equation where a quadratic polynomial is equal to zero. It can be written as ax^2+bx+c=0 where a,b,c are the coefficients and x is the variable. A quadratic equation has always two complex solutions for x given by the formula x=-b/2a+sqrt(b^2-4ac)/2a and x=-b/2a-sqrt(b^2-4ac)/2a. Examples of quadratic equations are x^2+x-2=0, 5x^2+6x=0, x^2+1=0 etc.
The answer is 4a^2.
20 = 1Consider what is the value of 2a ÷ 2a? Any number divided by itself is 1. Thus:2a ÷ 2a = 1The law of indices says that when dividing, they are subtracted, for example:25 ÷ 22 = (2 x 2 x 2 x 2 x 2) ÷ (2 x 2) = 2 x 2 x 2 = 23 = 25-2So 2a ÷ 2a is (also):2a ÷ 2a = 2a-a = 20Since any number subtracted from itself is 0 (= a - a). This must have the same value as before, thus:20 = 1The 2 above can be replaced by any number x which means that any number to the power 0 is 1:x0 = 1
The height of an equilateral triangle is √3/2 x side_length. So for an equilateral triangle of side length 2a, the area is: area = 1/2 x base x height 1/2 x (2a) x (√3/2 x 2a) = √3 a2
2a2
Factor them. 2 x 2 x a = 4a 2 x 5 x a x a = 10a2 Select the common factors. 2 x a = 2a, the GCF.
144a2b
2a - a = a
a x a means that a is multiplied by a. 2a means that a is multiplied by 2. Unless a happens to be 2, a x a will give a different result.The difference is a x (a-2). for example if a = 2, then the difference is zero. If a = 3, the difference is 3The operators are different: 2a = a + a (addition).
4a
x + 2a
2x^2 - 21x + c = 0 x^2 - 21x/2 + c/2 = 0 (x + a)(x + 2a)= x^2 - 21x/2 + c/2 x^2 + 3a + 2a^2 3a = -21/2 ------> a = -7/2 2a^2 = c/2 ---> 49/2 = c/2 ---> c = 49
The quadratic formula originated from the concept of completing the square. let's take ax2 + bx + c = 0. To complete the square, solve for x. Subtract c. ax2 + bx = -c. Then divide by a [notice- if there is no a value, then a=1]. x2 + bx/a = -c/a. Add (b/2a)2 to both sides. x2 + bx/a + b2/4a2 = -c/a + b2/4a2 Factor/Reformat. (x + b/2a)2 = (b2-4ac) / 4a2 (x + b/2a)2 = [(b2-4ac) / 2a]2 Square-root both sides. x + b/2a = ± √(b2-4ac) / 2a Subtract b/2a. x = -b/2a ± √(b2-4ac) / 2a Combine terms. x = [-b ± √(b2-4ac)] / 2a