ZA and B are supplementary mZA= 2n and mZB = 3n + 20
Find mZB
Am B = 12
B) mzB = 62
m B= 116
Dm B = 148

< A+< B =180

2n + 3n +20 =180

5n = 160

n = 32

(B= 116

answer is C

what i would say the best answer is a. 40.5

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92