Question

先化简 再计算 (x+2)(x-1)分之1+x÷(x-2+x+2分之3)其中x=2分之1

详细步骤！ 谢谢

Answer 1

(1+x)/[ (x+2)(x-1)]÷[x-2+3/(x+2)]
=(1+x)/[ (x+2)(x-1)]÷[(x²-4+3)/(x+2)]
=(1+x)/[ (x+2)(x-1)]÷[(x²-1)/(x+2)]
=(1+x)/[(x+2)(x-1`)]×(x+2)/[(x+1)(x-1)]
=1/(x-1)²
∵x=1/2
∴原式=1/(1/2-1)²=4

Answer 2

原式=(1+X)/(X+2)(X-1)］÷{［(X^2-4)+3］/(X-2)}
=(1+X)/(X+2)(X-1)*(X+2)/(X+1)(X-1)
=1/(X-1)^2
当X=1/2时，
原式=1÷(1/4)=4。