Let's factorise it :

![\: {\qquad \dashrightarrow \sf {x}^{3} (x + 3) + [-5(x + 3)] }](https://tex.z-dn.net/?f=%5C%3A%20%7B%5Cqquad%20%20%5Cdashrightarrow%20%5Csf%20%20%20%20%7Bx%7D%5E%7B3%7D%20%28x%20%2B%203%29%20%2B%20%5B-5%28x%20%2B%203%29%5D%20%20%7D)
Using Distributive property we get :



⠀
Therefore,

I think best word to insert in the blank is the term "bisecting".
An altitude of a triangle is a line or segment that passes through a vertex of the triangle and is bisecting <span>to the line containing the opposite side.
</span>"Bisect<span>" means to divide into two equal parts which is true for the altitude of a triangle.</span>
Answer:
Step-by-step explanation:
t - 1 - t^3 - 4t
-t^3 - 3t