Answer:
a) 137.9°
b) 12.2° (please refer to explanation because I didn't know what to round to)
Explanation:
1a) A supplementary angle will equal 180°, so you must subtract 42.1 from 180
180-42.1 = 137.9
1b) A complementary angle will equal 90°, so you need to use the expression given and add an x for the other part of 90°
8x-20+x = 90
9x-20=90
9x=110
x=12.2