Question 1194130
If you prefer two variables:


x, the meas of the acute angle
y, the meas of the obtuse angle
{{{x+y=140}}}


Supplement of y, {{{180-y}}}
Complement of x, {{{90-x}}}


The description second sentence
{{{2(180-y)+3(90-x)=340}}}

{{{360-2y+270-3x=340}}}

{{{-3x-2y=340-360-270}}}

{{{3x+2y=290}}}


system:  {{{system(x+y=140,3x+2y=290)}}}


multiply the first by 2
{{{system(2x+2y=280,3x+2y=290)}}}



{{{system(highlight(x=10),highlight(y=130))}}}