a: =>4x3=108
=>x3=27
=>x=3
b: =>x+3+5 chia het cho x+3
\(\Leftrightarrow x+3\in\left\{1;-1;5;-5\right\}\)
hay \(x\in\left\{-2;-3;2;-8\right\}\)
d: \(\Leftrightarrow4x+4+1⋮x+1\)
\(\Leftrightarrow x+1\in\left\{1;-1\right\}\)
hay \(x\in\left\{0;-2\right\}\)