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 = 9 and x = -1, what is the value of -7a(a - x)?
| -18 | |
| 198 | |
| -630 | |
| -672 |