.m(x-y)²-x+y 5(y-x)²+3(x-y) 15*(a-b)²-3y(b-a)

2个回答

  • m(x-y)²-x+y

    =m(x-y)²-(x-y)

    =(x-y)(mx-my-1)

    5(y-x)²+3(x-y)

    =5(x-y)²+3(x-y)

    =(x-y)(5x-5y+3)

    15*(a-b)²-3y(b-a)

    =15(a-b)²+3y(a-b)

    =3(a-b)(5a-5b+y)

    6(m-n)³-12(n-m)²

    =6(m-n)³-12(m-n)²

    =6(m-n)²(m-n-2)

    13/(x-4)-10/(x-3)=1/(x-1)

    去分母,两边同时乘以(x-4)(x-3)(x-1)得:

    13(x-3)(x-1)-10(x-4)(x-1)=(x-3)(x-4)

    13(x²-4x+3)-10(x²-5x+4)=x²-7x+12

    整理:2x²+5x-13=0

    解得x1=(-5-√129)/4,x2=(-5+√129)/4

    x1,x2均是原方程的根