## Introductory Algebra for College Students (7th Edition)

$x^{2}$ + 9x
(-3$x^{2}$ + x) + (4$x^{2}$+ 8x) The like terms are -3$x^{2}$ and 4$x^{2}$ containing the same variable to the same power($x^{2}$), as well as x and 8x (both containing x) . We begin by grouping these pairs of like terms. ( -3$x^{2}$ + 4$x^{2}$)+(x + 8x) = $x^{2}$ + 9x