Làm hộ em bài 2,3 với ạ em cần gấppppp

Câu `2:`

`a) ((x+5)^2-9)/(x^2+4x+4) (ĐKXD: x ne -2)`

`= ((x+5)^2 - 3^2)/(x+2)^2`

`= ((x+5-3)(x+5+3))/(x+2)^2`

`= ((x+2)(x+8))/(x+2)^2`

`= (x+8)/(x+2)`

`b) 2 - x/(x-6) + 36/(x^2-6x)(DKXD: x ne 6; x ne 0)`

`= (2x(x-6))/(x(x-6)) - x^2/(x(x-6)) + 36/(x(x-6))`

`= (2x^2-12x-x^2+36)/(x(x-6))`

`= (x^2-12x+36)/(x(x-6))`

`= (x-6)^2/(x(x-6))`

`= (x-6)/x`

`c) (2x)/(x+3) - (2x-30)/(9-x^2)+(x+1)/(x-3)(DKXD: x ne 3; x ne -3)`

`= (2x(x-3))/((x-3)(x+3)) + (2x-30)/((x-3)(x+3)) + ((x+3)(x+1))/((x-3)(x+3))`

`= (2x^2-6x+2x-30+x^2+x+3x+3)/((x-3)(x+3))`

`= (3x^2-27)/((x-3)(x+3))`

`= (3(x^2-9))/((x-3)(x+3))`

`= (3(x-3)(x+3))/((x-3)(x+3))`

`= 3`

Câu `3:`

`a) x/(xy+y^2)-y/(x^2+xy)(DKXD: x ne 0)`

`= x/(y(x+y))-y/(x(x+y))`

`= x^2/(xy(x+y)) - y^2/((xy(x+y))`

`= (x^2-y^2)/(xy(x+y))`

`= ((x-y)(x+y))/(xy(x+y))`

`= (x-y)/(xy)`

`b) (4x-1)/(3xy^2) - (7x-1)/(3xy^2)(ĐKXD: x ne 0)`

`= (4x-1-7x+1)/(3xy^2)`

`= (-3x)/(3xy^2)`

`= -1/y^2`

`c) (x^2-4x+19)/((x+3)(x-2)) + 3/(2-x) + 5/(x+3)(DKXD: x ne 2; x ne -3)`

`= (x^2-4x+19)/((x+3)(x-2)) - 3/(x-2) + 5/(x+3)`

`= (x^2-4x+19)/((x+3)(x-2)) - (3(x+3))/((x+3)(x-2)) + (5(x-2))/((x+3)(x-2))`

`= (x^2-4x+19-3x-9+5x-10)/((x+3)(x-2))`

`= (x^2-2x)/((x+3)(x-2))`

`= (x(x-2))/((x+3)(x-2))`

`= x/(x+3)`