解方程2题:a²-2ab+b²-3a+3b-10;(x+1)(x-1)-x-10 求快啊
问题描述:
解方程2题:a²-2ab+b²-3a+3b-10;(x+1)(x-1)-x-10 求快啊
答
你这两道不是方程,是代数式,应该是分解因式吧?
a²-2ab+b²-3a+3b-10
=(a-b)²-3(a-b)-10
=[(a-b)+2]*[(a-b)-5]
=(a-b+2)(a-b-5)
(x+1)(x-1)-x-1
=(x+1)(x-1)-(x+1)
=(x+1)(x-1-1)
=(x+1)(x-2)第二题(x+1)(x-1)-x-10,最后不是-1是-10(x+1)(x-1)-x-10
=x²-1-x-10
=x²-x-11
=x²-x+1/4-1/4-11
=(x-1/2)²-45/4
=(x-1/2)²-[2分之3根号5)²
=(x-1/2+2分之3根号5)(x-1/2-2分之3根号5)