Answer:
We have that:

And we want to find the value of g(4)
Then we are evaluating the function g(x) in x = 4, this means that we need to locate all the "x" in g(x), and replace them by 4.
If we do that, we get:

Now we can just solve this to get:

Unfortunately, this item does not come with any figure to illustrate the lengths of the rectangle. However, it may be noted that by connecting two opposite vertices of a rectangle by a diagonal, we form a right triangle. We may then use the Pythagorean theorem to solve for the answer.
a² + b² = c²
c in this equation is the length of the diagonal, a and b are the lengths of the sides.
3x^2 + 21x
Is the answer without a doubt.
Answer:4
Step-by-step explanation: