# How do you use the quadratic formula to solve #3x^2- 8x -15 =0 #?

##### 1 Answer

Feb 12, 2017

#### Explanation:

This is really worth trying to remember. I did it many years ago by making a point of writing it out for every question I attempted. Repetition is the key.

The standard form is:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Given:

Set

So by substitution we have: