Both angles form a complementary angle, which means that their sum is equal 90 degree.
5x+7 +3x+11=90 Combine like terms
8x+18=90 Subtract 18 in both sides
8x =72 Divide by 8 in both sides to isolate x
x=9
As you have the value of x, you can find the value of each expression
5(9)+7= 52 3(9)+11=38
The correct answer is letter C, 52 and 38.