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 z = -1, what is the value of a(a - z)?
| 198 | |
| 90 | |
| 0 | |
| 560 |