Step-by-step explanation:
<u><em>f(a):</em></u>
So for this you simply plug in "a" as x, and this doesn't really do anything beside replace all values with x, so you just have the equation:
<u><em>2 f(a):</em></u>
So for this one, you want to represent f(a) using the equation it's equal to (5a + 4), and substitute it in for f(a). In doing so, you get the expression:
2*f(a) -> 2(5a + 4) -> 10a + 8
<u><em>f(2a):</em></u>
So this is very similar to the first question, although you will have to do some multiplication. So just plug in 2a as "x" to get the equation:
<u><em>f(a+2):</em></u>
Basically the same process, you plug in (a+2) as "x" and simplify:
<u><em>f(a) + f(2)</em></u>:
This is similar to the second question, and you simply want to replace the f(a) with the equation that represents it (5a + 4) and same thing for f(2) = 5(2) + 4