\(5+5\left( x+4 \right) \le 20\\ \\ 5\left\{ 1+\left( x+4 \right) \right\} \le 20\\ \\ \frac { 1 }{ 5 } \cdot 5\left\{ 1+\left( x+4 \right) \right\} \le 20\cdot \frac { 1 }{ 5 }\)
\(\ \\ 1+\left( x+4 \right) \le 4\\ \\ 1+x+4\le 4\\ \\ x+5\le 4\\ \\ x\le 4-5\\ \\ x\le -1\)