Question

x/2x+6-x/2x+2=3x+2/(x+1)(x+3)

Answer 1

`x/(2x+6) -x/(2x+2) = (3x+2)/[(x+1)(x+3)]  (đk : x ne -1 ; x ne -3)`

`<=>`\(\dfrac{x\left(x+1\right)}{2\left(x+1\right)\left(x+3\right)}-\dfrac{x\left(x+3\right)}{2\left(x+1\right)\left(x+3\right)}=\dfrac{2\left(3x+2\right)}{2\left(x+1\right)\left(x+3\right)}\)

`=> x^2 +x -x^2 -3x = 6x +6`

`<=> x -3x-6x =6`

`<=> -8x =6`

`<=> x =-3/4(t//m)`

Vậy `S={-3/4}`

Answer 2

\(\Leftrightarrow x\left(x+1\right)-x\left(x+3\right)=6x+4\)

=>6x+4=x^2+x-x^2-3x=-2x

=>8x=-4

=>x=-1/2(nhận)