Question 318762
1.{{{A+S=180}}}
2.{{{A=S-40}}}
Substitute eq. 2 into eq. 1,
{{{(S-40)+S=180}}}
{{{2S-40=180}}}
{{{2S=220}}}
{{{highlight(S=110)}}} degrees
Then from eq. 2,
{{{A=110-40}}}
{{{highlight(A=70)}}} degrees