Note the equal sign. What you do to one side, you do to the other. Isolate the a.
Add 4 to both sides
a- 4 (+4) = 15 (+4)
a = 15 + 4
a = 19
19 is your answer for a
hope this helps
Answer:
The answer to your question is below
Step-by-step explanation:
csc α - cot α = 
Work with the left part

Simplify

Multiply by the reciprocal
Simplify

Remember that
sin²α = 1 -cos²α
Substitute the previous equation

Simplify
The identity i proved.
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Answer:
Q: 160 R: 504 S: 480 T: 130 other answer: C
Step-by-step explanation: