Question 484179
First one has to know what "complementary" means, which (if degrees are used instead of radians) is X + Y = 90.
Subtitute to get 16z-9 + 4z+3 = 90
Add like terms (powers of z) to get 20z - 6 = 90
Both +6: 20z = 96
Both /20: z = 96/20 = 24/5
Sub this for z in the 2 angle expressions:
16(24/5)-9 = (386-45)/5 = 339/5 = 67.8
4(24/5)+3 = (96+15)/5 = 111/5 = 22.2
Important double check: these add to 90.