Find the angles. I cant figure it out

Question

For a given triangle, the measure of angle A is 10° less than three times the measure of angle B. The measure of angle C is one-fifth the sum of the measures of angles A and B. Knowing that the sum of the measures of the angles of a triangle equals 180°, find the measure of each angle.

Answer 1

A = 3B - 10

 

C = (A + B)/5

 

A + B + C = 180

 

Use substitution to solve.  Can you take it from here?