Answer: 18°
Explanation:
Complementary angles are the angles that when we add them together, the value will equal 90°.
In this question, we've to add both angles and equate them to 90°. This will be:
(2x - 4) + (5x + 17) = 90
2x - 4 + 5x + 17 = 90
Collect like terms
2x + 5x = 90 + 4 - 17
7x = 77
x = 77/7
x = 11
Angle A will be:
= (2x-4)
= 2(11) - 4
= 22 - 4
= 18°