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 x = 9, what is the value of 9a(a - x)?
| -126 | |
| 77 | |
| 128 | |
| 1080 |