You can factor a parabola by finding its roots: if
has roots , then you have the following factorization:
In order to find the roots, you can use the usual formula
In the first example, this formula leads to
So, you can factor
The same goes for the second parabola.
As for the third exercise, simply plug the values asking
you get
Add 3 to both sides:
Divide both sides by 1.5: