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)?
| 432 | |
| 72 | |
| -126 | |
| 0 |