HURRY I NEED HELP!!!

Answer:
complementary angles add to 90°
create an equation for both of the angles:
90= 3x + 10 + x
solve for x by combining like terms:
90= 4x + 10
solve for x by removing 10 from both sides:
80= 4x
solve for x by dividing by 4 on both sides:
20=x
and you get your answer of x=20
To check your answer plug in 20 for x in the equation above:
90= 3(20) + 10 + 20
90= 60 + 30
90=90