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.)
Solve a - 8a = -a + 3x + 9 for a in terms of x.
| 2x + 2 | |
| -\(\frac{1}{13}\)x + \(\frac{2}{13}\) | |
| 5\(\frac{1}{2}\)x + 4\(\frac{1}{2}\) | |
| 3x + 1 |