Question 470153
if {{{b=4x-7}}}, then {{{3b=3(4x-7)=12x-21}}}
if {{{ a=2x+3}}}, then {{{5a=5(2x+3)=10x+15}}}
{{{3b=5a}}}, so {{{12x-21=10x+15}}}
{{{12x-10x=15+21}}}
{{{2x=36}}}
{{{x=36/2}}}
{{{x=18}}}