Đáp án:
`P=2/\sqrt[x-1]`
Giải thích các bước giải:
`P=2(1/\sqrt[x-1]-1/(\sqrt[x-1]+1)):\sqrt[x-1]/(x+sqrt[x-1]-1`
`P=2.(\sqrt[x-1]+1-1(\sqrt[x-1]))/(\sqrt[x-1].(\sqrt[x-1]+1)):\sqrt[x-1]/(x+sqrt[x-1]-1)`
`P=2.(\sqrt[x-1]+1-\sqrt[x-1])/(\sqrt[x-1].(\sqrt[x-1]+1)):\sqrt[x-1]/(x+sqrt[x-1]-1)`
`P=(2.1)/(\sqrt[x-1].(\sqrt[x-1]+1)).(x+sqrt[x-1]-1)/\sqrt[x-1]`
`P=2/(\sqrt[x-1]^2.\sqrt[x-1]).(x+sqrt[x-1]-1)/\sqrt[x-1]`
`P=2/(x-1+\sqrt[x-1]).(x+sqrt[x-1]-1)/\sqrt[x-1]`
`P=2/(x+\sqrt[x-1]-1).(x+sqrt[x-1]-1)/\sqrt[x-1]`
`P=2/\sqrt[x-1]`
