Remove the brackets
-5a + 9b + 7a combine -5a and 7a
7a - 5a + 9b
2a + 9b Answer
Don't go any further. There is nothing else to do. These are unlike terms and cannot be reduced or combined.
Answer:

Step-by-step explanation:
Given

Required
Determine an equivalent expression
In trigonometry:

In 

Substitute
for
in 


Hence, the equivalent expression is: 
I’m pretty sure it’s chad