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 = 7 and z = -3, what is the value of 9a(a - z)?
| 24 | |
| 630 | |
| 56 | |
| 168 |