Answer:
15
Step-by-step explanation:
Complementary angles add to 90 degrees
8x+27 + 6x-21 = 90
Combine like terms
14x+6 = 90
Subtract 6 from each side
14x+6-6 = 90-6
14x = 84
Divide by 14
14x/14 = 84/14
x=6
We want angle B
B = 6x-21 = 6*6-21 =36-21 = 15
