6x^2+7xy+2y^2-8x-5y+2=(2x+y)(3x+2y)-8x-5y+2下面我们用待定系数法来解答(2x+y)(3x+2y)-8x-5y+2=（2x+y+m)(3x+2y+n)=6x^2+7xy+2y^2+(3m+2n)x+(n+2m)y+mnmn=23m+2n=-8n+2m=-5n=-1m=-2(2x+y)(3x+2y)-8x-5y+2=（2x+y-2)(3x+2y-1)
