Question 37726
Let call the angle X
Its complement will be 90-x
Its supplement will be 180-x

(180-x)+15 = 4(90-x)
180-x+15 = 360-4x
4x-x = 360-180-15
3x = 165
x = 55

Prove

The complement of 55 is 35
And the supplement of 55 is 125

Now we must see if the relation stated holds

125+15 = 4(35)
125+15 = 140  The measure of the supplement of an angle is 15 degrees less than four times the measure of the complement.
140 = 140

Therefore the solution of the problem is given by an angle of 55 degrees.