N 2.
Select the correct answer.
What is the expanded equivalent of sin(a + b)?
OA.
sin a cos b- cos a sin b
OB.
sin a cos b + cos a sin b
O c.
cos a cos b- sin a sin b
D.
cos a cos b + sin a sin b

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.