Introductory Algebra for College Students (7th Edition)

3$x^{3}$ + 2$x^{2}$ - 9x +7
(2$x^{2}$- 6x+ 7) + (3$x^{3}$ -3x) The like terms are 2$x^{2}$ , 3$x^{3}$ , -6x and -3x (both containing x) and the constant terms 7. We begin by grouping these pairs of like terms. = 2$x^{2}$ + 3$x^{3}$ +(-6x -3x)+ 7 = 3$x^{3}$ + 2$x^{2}$ - 9x +7