3(x-y)的平方-4(x-y)+7(x-y)-6(y-x)的平方-2(y-x)
原式=3(x-y)的平方-4(x-y)+7(x-y)-6(x-y)的平方+2(x-y)
=(3-6)(x-y)^2+(-4+7+2)(x-y)
=-3(x-y)^2+5(x-y)
供参考
3(x-y)的平方-4(x-y)+7(x-y)-6(y-x)的平方-2(y-x)
原式=3(x-y)的平方-4(x-y)+7(x-y)-6(x-y)的平方+2(x-y)
=(3-6)(x-y)^2+(-4+7+2)(x-y)
=-3(x-y)^2+5(x-y)
供参考