## Algebra 1: Common Core (15th Edition)

No, the sum of two trinomials is not always a trinomial. Example is provided below. (3$x^{2}$+2x-9)-(2$x^{2}$+2x-8) = 3$x^{x}$-2$x^{2}$+2x-2x-9+8 =$x^{2}$-1