Answer: -16/65
Step-by-step explanation:
Drawing the right triangle (as attached) gives us that 
Also, 
This means our original expression is equal to:
![\cos \left[\arcsin \left(\frac{12}{13} \right)+\arcsin \left(\frac{3}{5} \right) \right]](https://tex.z-dn.net/?f=%5Ccos%20%5Cleft%5B%5Carcsin%20%5Cleft%28%5Cfrac%7B12%7D%7B13%7D%20%5Cright%29%2B%5Carcsin%20%5Cleft%28%5Cfrac%7B3%7D%7B5%7D%20%5Cright%29%20%5Cright%5D)
Using the cosine addition formula, which states
, we get this itself is equal to:

Since
, we know that:

Similarly, cos(arcsin(3/5))=4/5.
This means the given expression is equal to:

When you multiply powers with the same base, you sum the exponents:

So, in this case, you have

First, distribute the (1/2) into (4x+12) by multiplying them.
The equation becomes:
2x + 6 + 5x = 30
On the left side, combine “like terms” through addition.
7x + 6 = 30
Subtract 6 from both sides:
7x = 24
Finally, get x alone by dividing both sides by 7:
x = 24/7, or if you wanted to round the decimal answer, it’s about 3.429.
I’m positive the answer is B if it isn’t I’m sorry
Answer: A
Step-by-step explanation: