x-3/x²-1 ÷ (x-3)(x+1)/x²+2x+1 + 1/x+1,其中x=2

问题描述:

x-3/x²-1 ÷ (x-3)(x+1)/x²+2x+1 + 1/x+1,其中x=2

你求的是什么? 如果是结果 你直接把X=2代进去就行了呀!

8.5

x-3/x²-1 ÷ (x-3)(x+1)/x²+2x+1 + 1/x+1
=(x-3)(x+1)²/(x+1)(x-1)(x-3)(x+1)+1/x+1
=x+1/x-1+1/x+1
=(2+1)/(2-1)+1/(2+1)
=3+1/3=10/3

x-3/x²-1 ÷ (x-3)(x+1)/x²+2x+1 + 1/x+1
=(x-3)/(x-1)(x+1)÷(x-3)(x+1)/(x+1)(x+1)+ 1/x+1
=1/(x+1)+1/(x+1)
=2/(x+1)
代入x=2
=2/3