Question

If the degree measure of an angle is 40° less than 3 times the degree measure of its supplementary angle, what is the degree measure of the angle?

Answer 1

Let x° be this angle and it's supplementary angle is 180°-x°;
Now translate English into Mth language:

x° = 3(180°-x°) - 40°

Solve for x°: x° = 540° - 3x° - 40°

4x° = 500° and x° =125°