Answer:
+12+8=+20
Step-by-step explanation:
Hope it helps you!
Answer:

Step-by-step explanation:
Given:


Need:

First, let's look at the identities:
sum: 
difference: 
The question asks to find sin(A - B); therefore, we need to use the difference identity.
Based on the given information (value and quadrant), we can draw reference triangles to find the simplified values of A and B.
sin(A) = 
cos(A) = 
sin(B) = 
cos(B) = 
Plug these values into the difference identity formula.


Multiply.

Add.

This is your answer.
Hope this helps!
Answer:
Step-by-step explanation:

Combine like terms. 1/4 and 7/8 are like terms and LCD of 4 and 8 is 8
9/10y and -3/5y are like terms and LCD of 10 , 5 is 10
