Answer:
B.

Step-by-step explanation:
Explanation:



follows from the fact that the cosine function is

-periodic, which means

. Roughly speaking, this is the same as saying that a point on a circle is the same as the point you get by completing a full revolution around the circle (i.e. add

to the original point's angle with respect to the horizontal axis).
If you make another complete revolution (so we're effectively adding

) we get the same result:

. This is true for any number of complete revolutions, so that this pattern holds for any even multiple of

added to the argument. Therefore

for any integer

.
Next, because

, it follows that

is also true for any integer

. So we have

The rest follows from considering either case and solving for

.
f(x)=4x-6
g(x) = f(2x)
Substitute 2x into the first equation, which you get
f(2x)=8x-6
<h2><u><em>
So, g(x)=8x-6</em></u></h2>
Answer:
15(2r^2+2r+5)
Step-by-step explanation:
I'm more of a guess and check type of person, but 15 x 2r^2 = 30r^2, 15 x 2r = 30r, and 15 x 5 = 75