A variable is a letter that represents a number. An expression that contains at least one variable is called variable expression, also called algebraic expression. A variable expression has one or more terms. A term is a number, a variable, or a product of numbers and variables. For example,3(x^2)y + 2xy + x - 7 is a variable expression, where you have 4 terms.When working with variable expression, you often use the substitution principle:If a = b, then a may be replaced by b in any expression.The set of numbers that a variable may be represent is called replacement set, or domain, of the variable. To evaluate a variable expression, you replace each variable with one of its values and simplify the numerical expression that results.Example: Evaluate the expression 2x - 4y for x = 5 and y = -9.Solution:2x - 4y= 2(5) - 4(-9)= 10 + 36=46
X/(y+7)
You have to substitute a value for the letter variable in the expression. This is what we call evaluating the algebraic expression. An example would be 3x+1=7, when x=2.
A number, f, less than 7.
The value of that type of expression depends on the value of the variable, in this case, "x".
Translate the following phrase into a variable expression. Use the letter d to name the variable. …7 times the distance
3n-7
It is suppose to be k/3 minus 7
The algebraic expression ( 7 + \frac{6}{k} ) can be expressed in words as: "Seven plus six divided by k." This phrase describes the operation of adding 7 to the result of dividing 6 by ( k ).
7
y
2
5+3x(7-2)
7 is the coefficient of the variable d
7
A variable is a letter that represents a number. An expression that contains at least one variable is called variable expression, also called algebraic expression. A variable expression has one or more terms. A term is a number, a variable, or a product of numbers and variables. For example,3(x^2)y + 2xy + x - 7 is a variable expression, where you have 4 terms.When working with variable expression, you often use the substitution principle:If a = b, then a may be replaced by b in any expression.The set of numbers that a variable may be represent is called replacement set, or domain, of the variable. To evaluate a variable expression, you replace each variable with one of its values and simplify the numerical expression that results.Example: Evaluate the expression 2x - 4y for x = 5 and y = -9.Solution:2x - 4y= 2(5) - 4(-9)= 10 + 36=46
X/(y+7)