因式分解3x^2+5xy
因式分解3x^2+5xy-2y^2+x+9y-4
因式分解3x^2+5xy-2y^2+x+9y-4 3x^2+5xy-2y^2+x+9y-4=(3x-y)*(x+2y)+x+9y-4 =(3x-y+4)(x+2y-1).