Đáp án+Giải thích các bước giải:
`(x+1)^2+(x+1)^2/(x+2)^2=8`
`⇔(x+1)^2+(x+1)^2/(x+2)^2+2(x+1).(x+1)/(x+2)-2(x+1).(x+1)/(x+2)=8`
`⇔[(x+1)^2-2(x+1).(x+1)/(x+2)+(x+1)^2/(x+2)^2]+2(x+1).(x+1)/(x+2)=8`
`⇔[(x+1)^2-2(x+1).(x+1)/(x+2)+((x+1)/(x+2))^2]+2(x+1).(x+1)/(x+2)=8`
`⇔(x+1-(x+1)/(x+2))^2+2(x+1).(x+1)/(x+2)=8`