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 = -7, what is the value of 9a(a - z)?
| 0 | |
| -48 | |
| -270 | |
| -20 |