What if the paycheck for your summer job were represented by the algebraic expression
When we are given an algebraic expression, one of the most common things we might have to do with it is evaluate it for some given value of the variable. The following example illustrates this process.
To find the solution, we substitute 12 for
Note: At this stage of the problem, we place the substituted value in parentheses. We do this to make the written-out problem easier to follow, and to avoid mistakes. (If we didn’t use parentheses and also forgot to add a multiplication sign, we would end up turning
Many expressions have more than one variable in them. For example, the formula for the perimeter of a rectangle in the introduction has two variables: length
The area of a trapezoid is given by the equation
To find the solution to this problem, we simply take the values given for the variables
The area of the trapezoid is 100 square centimeters.
Watch this video for help with the Examples above.
- When given an algebraic expression, one of the most common things we might have to do with it is evaluate it for some given value of the variable. We substitute the value in for the variable and simplify the expression.
Evaluate 1-8 using
For 9-11, the weekly cost
- What is the cost of producing 1000 remote controls?
- What is the cost of producing 2000 remote controls?
- What is the cost of producing 2500 remote controls?