Answer:
see explanation
Step-by-step explanation:
Complementary angles sum to 90°, hence
∠A + ∠B = 90° ← substitute values
4x - 1 + 5x + 19 = 90, that is
9x + 18 = 90 ( subtract 18 from both sides )
9x = 72 ( divide both sides by 9 )
x = 8
Hence
∠A = 4x - 1 = (4 × 8) - 1 = 32 - 1 = 31°
∠B = 5x + 19 = (5 × 8) + 19 = 40 + 19 = 59°