Đáp án:
`x\in{-3;-2}`
Trình bày lời giải:
`( x + 3 )^2 = ( x + 3 )^5`
`=>(x+3)^2-(x+3)^5=0`
`=>(x+3)^2 . 1-(x+3)^2 . (x+3)^3=0`
`=>(x+3)^2 .[1-(x+3)^3]=0`
`=>[((x+3)^2=0),(1-(x+3)^3=0):}`
`=>[(x+3=0),((x+3)^3=1-0=1):}`
`=>[(x=0-3=-3),(x+3=1):}`
`=>[(x=-3),(x=-2):}`
Vậy `x\in{-3;-2}`