(5x^2+6x-7)+[-4x^2-( )] =x^2+2x+1 （x^3-4x^2y+11xy^2-y^3）+（）=x^3+3_数学解答

(5x^2+6x-7)+[-4x^2-( )] =x^2+2x+1 （x^3-4x^2y+11xy^2-y^3）+（）=x^3+3x^2y-5xy^2

人气：423 ℃　时间：2020-09-29 12:49:04

解答

(5x^2+6x-7)+[-4x^2-(4x-8 )] =x^2+2x+1
（x^3-4x^2y+11xy^2-y^3）+（7x^y-16xy^2+y^3）=x^3+3x^2y-5xy^2