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 -7a + 4a = 8a - 2y + 9 for a in terms of y.
| -\(\frac{1}{4}\)y - 2 | |
| 15y + 4 | |
| \(\frac{2}{5}\)y - \(\frac{3}{5}\) | |
| \(\frac{13}{15}\)y - \(\frac{7}{15}\) |