Giải giùm mik bài này

Đáp án+Giải thích các bước giải:

 `P=(1/(sqrta-1)-1/sqrta):((sqrta+1)/(sqrta-2)-(sqrta+2)/(sqrta-1))(a>0,a ne 1)`

`a)P=(sqrta/(sqrta(sqrta-1))-(sqrta-1)/(sqrta(sqrta-1))):(((sqrta+1)(sqrta-1))/((sqrta-1)(sqrta-2))-((sqrta+2)(sqrta-1))/((sqrta-1)(sqrta-2)))`

`P=(sqrta-sqrta+1)/(sqrta(sqrta-1)):(a-1-a+4)/((sqrta-1)(sqrta-2))`

`P=1/(sqrta(sqrta-1))*((sqrta-1)(sqrta-2))/3`

`P=(sqrta-2)/(3sqrta)`

`b)P=1/4`

`<=>(sqrta-2)/(3sqrta)=1/4`

`<=>4sqrta-8=3sqrta`

`<=>sqrta=8`

`<=>a=64(tmđk)`

`c)a=9-4sqrt5`

`a=5-2.2.sqrt5+4`

`a=(sqrt5-2)^2`

`=>P=(sqrt5-2-2)/(3(sqrt5-2))`

`P=((sqrt5-4)(sqrt5+2))/(3(5-4))`

`P=(5+2sqrt5-4sqrt5-8)/(3.1)`

`P=(-3-2sqrt5)/3`