Question 947016
{{{A+B=90}}}
{{{B=4A-6}}}
Substitute,
{{{A+4A-6=90}}}
{{{5A=96}}}
{{{A=96/5}}}
So then,
{{{B=4(96/5)-6}}}
{{{B=384/5-30/5}}}
{{{B=354/5}}}