已知x^2+2x=2,求代数式(x-1)2+(x+3)(x-3)+(x-3)(x-1)的值
问题描述:
已知x^2+2x=2,求代数式(x-1)2+(x+3)(x-3)+(x-3)(x-1)的值
计算(a-b)^5(b-a)^3
答
(x-1)^2+(x+3)(x-3)+(x-3)(x-1)
=x^2-2x+1+x^2-9+x^2-4x+3
=3x^2-6x-5
=3(x^2-2x)-5
=3*2-5
=1
注:x^2+2x=2应为x^2-2x=2
(a-b)^5(b-a)^3
=-(a-b)^5(a-b)^3
=-(a-b)^8