①.X²;-2X+1/X²;-1÷X²;-X/X+1 ②.a-1/a²;-4a+4÷a²;-1/a²;-4 ③.x³;-x²;/x²;-x÷x²;-2x/x-1 ④.(x-y)²;/x+y÷1/y+x X 1/x-y 幫下忙嘛咯

①.X²;-2X+1/X²;-1÷X²;-X/X+1 ②.a-1/a²;-4a+4÷a²;-1/a²;-4 ③.x³;-x²;/x²;-x÷x²;-2x/x-1 ④.(x-y)²;/x+y÷1/y+x X 1/x-y 幫下忙嘛咯

1.原式=(x-1)^2/(x-1)(x+1)乘以x+1/x(x-1)
=(x-1)/(x+1)乘以(x+1/x(x-1)
=1/x
樓上的已經做了,那我還要提醒一下,第2題要化到最簡單,要把括弧打開,除了乘方不用.