Question 342926
{{{A+S=180}}}
{{{A=3S+18}}}
Substitute,
{{{(3S+15)+S=180}}}
{{{4S+15=180}}}
{{{4S=165}}}
{{{highlight(S=165/4)}}}degrees
Then,
{{{A=3(165/4)+15}}}
{{{A=495/4+60/4}}}
{{{highlight(A=555/4)}}}degrees