(-3x^y+2xy)-( )=4x^+xy
问题描述:
(-3x^y+2xy)-( )=4x^+xy
答
(-3x^y+2xy)-(4x^+xy)
=-3x^y+2xy-4x^-xy
=-3x^y+xy-4x^
所以填上-3x^y+xy-4x^