rút gọn ạ ,giúp tui vs

$#CheliKa$

`P = ( 1/(sqrt{a}-1) - 1/sqrt{a} ) ÷ ( (sqrt{a} + 1)/(sqrt{a}-2) - (sqrt{a}+2)/(sqrt{a}-1) )`

`P = [(1sqrt{a})/(sqrt{a}(sqrt{a}-1)) - (1(sqrt{a}-1))/(sqrt{a}(sqrt{a}-1)) ] ÷ [ ((sqrt{a} + 1)(sqrt{a}-1))/((sqrt{a}-2)(sqrt{a}-1)) - ( (sqrt{a}+2)(sqrt{a}-2) )/((sqrt{a}-2)(sqrt{a}-1)) ]`

`P = [ sqrt{a}/(sqrt{a}(sqrt{a}-1)) - (sqrt{a}-1)/(sqrt{a}(sqrt{a}-1)) ] ÷ [ ((sqrt{a} + 1)(sqrt{a}-1))/((sqrt{a}-2)(sqrt{a}-1)) - ( (sqrt{a}+2)(sqrt{a}-2) )/((sqrt{a}-2)(sqrt{a}-1)) ]`

`P = (sqrt{a}-(sqrt{a}-1))/(sqrt{a}(sqrt{a}-1)) ÷ ((sqrt{a} + 1)(sqrt{a}-1)-(sqrt{a}+2)(sqrt{a}-2))/((sqrt{a}-2)(sqrt{a}-1)) `

`P = (sqrt{a}-sqrt{a}+1)/(sqrt{a}(sqrt{a}-1)) ÷ ((a-1)-(a-4))/((sqrt{a}-2)(sqrt{a}-1))`

`P = 1/(sqrt{a}(sqrt{a}-1)) ÷ (a-1-a+4)/((sqrt{a}-2)(sqrt{a}-1))`

`P = 1/(sqrt{a}(sqrt{a}-1)) ÷ 3/((sqrt{a}-2)(sqrt{a}-1))`

`P = 1/(sqrt{a}(sqrt{a}-1)) . ((sqrt{a}-2)(sqrt{a}-1))/3`

`P = 1/(sqrt{a}) . (sqrt{a}-2)/3`

`P =(sqrt{a}-2)/(3sqrt{a})` .