X.(1+x)=16+x
x+x2=16+x
x-x+x2=16
x2=16
x2=42
=>x=4
\(x\left(1+x\right)=16+x\)
\(x+x^2=16+x\)
\(x+x^2-x=16\)
\(x^2=16\)
\(\Rightarrow\orbr{\begin{cases}x=4\\x=-4\end{cases}}\)
\(x.\left(1+x\right)=16+x\)
\(x+x^2=16+x\)
\(x-x+x^2=16\)
\(x^2=16\)
\(x^2=4^2\)
\(x=4\)