Question

15 + (x + 2)² : 3=18

Answer 1

`15+(x+2)^2 :3=18`

`(x+2)^2:3=18-15`

`(x+2)^2 :3=3`

`(x+2)^2 = 3xx3`

`(x+2)^2 = 9`

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

`=>x+2 = 3` hoặc `x +2=-3`

`=> x = 3-2` hoặc `x = -3-2`

`=> x = 1` hoặc `x=-5`

Answer 2

\(\left(x+2\right)^2:3=18-15< =>\left(x+2\right)^2:3=3< =>\left(x+2\right)^2=3\cdot3< =>\left(x+2\right)^2=9< =>\left(x+2\right)=3^2< =>\left[{}\begin{matrix}x+2=3\\x+2=-3\end{matrix}\right.< =>\left[{}\begin{matrix}x=1\\x=-5\end{matrix}\right.\)