When solving an equation with two variables, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)
If a = 8 and x = 7, what is the value of 9a(a - x)?
| 128 | |
| -80 | |
| 72 | |
| -18 |