3x + 5x - 2x
7a - 4 - 2a + 9
-2x + 8x - 5x
4y - 6 + 3y - 2
4(2a - 3) - 3(a - 5)
-2(3x - 1) + 5(x + 2)
\frac{2x - 1}{3} + \frac{x + 4}{2}
\frac{3a - 2}{4} - \frac{a - 5}{6}
2x - 3y
x^2 + 2y
-x^2 - y^2
\frac{y - x}{7}