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 = 1 and z = 9, what is the value of -2a(a - z)?
| 16 | |
| -42 | |
| -21 | |
| -30 |