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 = 9, what is the value of 4a(a - x)?
| 18 | |
| 648 | |
| 140 | |
| -20 |