Answer:
or
![x = -5](https://img.qammunity.org/2020/formulas/mathematics/middle-school/zf5mehbkfwgwkazcxj4wpsd6rvtvavpv9d.png)
Explanation:
To solve the quadratic equation we must factor the expression
Look for 2 numbers that when you multiply them, obtain the result -100 and when you add them, obtain the result -15.
You can verify that these numbers are -20 and 5
![-20 +5 = -15\\\\-20 * 5 = -100](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ftnvvcjh3pyng5e7c81p6s3a97v5qjdtra.png)
Then the polynomial factors are
![(x-20) (x + 5) = 0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/cd2nrfi3vywa0v8eaw7bf9um8m9a5lz8mh.png)
The zero product property says that if two terms
then
or
![b = 0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/q7zmyxtk3710g6uk09v0aylqtinjqpaxrh.png)
So
or
![(x + 5) = 0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4weei7ctxlivwtriyc5kzlmd2arzstpytn.png)
or
![x = -5](https://img.qammunity.org/2020/formulas/mathematics/middle-school/zf5mehbkfwgwkazcxj4wpsd6rvtvavpv9d.png)