I think it's A. I can't really see the graphs clearly. It's the one that crosses at (15,2)
soh cah toa
that is the saying I use
we will use cah
c is cos
a is ajacent
h is hypotinuse
to find cos K we need to do
adjacent / hypotenuse
can you do that and write it in the comments
+ √6 = √9
The first step is to get
by itself. We can do this by subtracting
from each side, and simplifying 
= 3 - 
Now we square both sides
5x = (3 -
)²
Using the formula (a - b)² = a² -2ab + b², (3 -
)² = 15 - 6
5x = 15 - 6
x = 