最后=-4x（x-2）²-10x过程，谢谢-4x³+16x²-26x =-2x(2x²-8x+13) =-2x{2(x²-4x+4-4)+13} =-2x{2(x-2)²-8+13} =-4x(x-2)²-10x x全部不是称号