More math and its my last question

We know that ∠1 equals ∠3, from that we can find x:

The sum of ∠1 and ∠2 must equal 180°:

Since we already know x, we can solve for y:

Result: x=10, y=6

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

the answer is d

for problems like this theres an app, its photomath that explains the problem and gives the answer hope i