ABCD is a rectangle. Angle A measures (4x - 15) °. Find x.

If the shape in question is a rectangle, we know for a fact that each angle is equal to 90 degrees (or a right angle). So, since any given angle is equal to 90, that includes angle A.

4x - 15 = 90

4x = 90 + 15

4x = 105

x = 105/4

x = 26.25