45.
For this, replace x in the equation for 4.

The answer is 29, or B.
46.
So firstly, we have to find what f(-10) is in the first equation. For this, replace x for -10 and solve.

Now that we know that f(-10) = 2, we can substitute that into the second equation and solve for k.

In short, the value of k is 3.