Question 986903
{{{A=3B}}}
{{{60-A=(55-B)-5}}}
Substituting,
{{{60-3B=55-B-5}}}
{{{60-3B=50-B}}}
{{{-2B=-10}}}
{{{B=5}}}
Then,
{{{A=3(5)}}}
{{{A=15}}}