Answer:
∠ ADE = 59°
Explanation:
The angles in a rectangle are right angles, then
∠ ABC = 90° , that is
4x + 15 + 13x + 7 = 90
17x + 22 = 90 ( subtract 22 from both sides )
17x = 68 ( divide both sides by 17 )
x = 4
Then
∠ CBE = 13x + 7 = 13(4) + 7 = 52 +7 = 59°
Since the sides in a rectangle are parallel then
∠ ADE = ∠ CBE ( alternate angles )
∠ ADE = 59°