Step-by-step explanation:
1. 
multiply

do both the numerator and denominater

Answer:
x = 64
Step-by-step explanation:
2x = 128
x = 64
Answer:
cos (theta) = √21/5
Step-by-step explanation:
sin (theta) = 2/5
(sin (theta))^2 = 4/25
4/25 + (cos (theta))^2 = 1
(cos (theta))^2 = 1 - 4/25 = 21/25
cos (theta) = √21/5
I think 45 but not too sure, lol sry