`a)-3(x+7)=-27`
`⇔x+7=9`
`⇔x=2`
Vậy `x=2`
`b)15(2-x)=-45`
`⇔2-x=-3`
`⇔x=2-(-3)`
`⇔x=5`
Vậy `x=5`
`c)4-2(x+1)=-24`
`⇔2(x+1)=4-(-24)`
`⇔2x+2=28`
`⇔2x=26`
`⇔x=13`
Vậy `x=13`
`d)5(x+9)=0`
`⇔x+9=0`
`⇔x=-9`
Vậy `x=-9`
`e)(x+7)(4-x)=0`
`→` \(\left[ \begin{array}{l}x+7=0\\4-x=0\end{array} \right.\)
`→` \(\left[ \begin{array}{l}x=-7\\x=4\end{array} \right.\)
Vậy `x∈{-7;4}`