Answer :
[tex]x-\ Ben's \ airplanes\\\\\
y- \ Cole's\ airplanes\\\\\
\left \{ {{x+y=36} \atop {y+8=x}} \right.\\\\
Substituting\ method:\\\\
y+8+y=36\\\\
2y=36-8\\\\
2y=28\ \ |:2\\\\
y=14\\\\ x=y+8=14+8=22 \\\\ Ben\ has\ 22\ airplanes. [/tex]