Question

What is the answer ?

Answer 1

∠ADB + ∠BDC = ∠ADC

39° + (3x - 4) = 8x + 5

3x - 4 = 8x + 5 - 39

3x - 4 = 8x - 34

34 - 4 = 8x - 3x

5x = 30

x = 6

∠ADC = 39° + (3(6) - 4) = 39 + 14 = 53°

Hope it helps!