Answer:
![x = \frac{ - b ± \sqrt{ {b }^(2) - 4ac } }{2a}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4josnhiahemewwrmd3cwdhdpw51eds14l4.png)
Explanation:
For example, we'll use this quadratic equation.
![{x}^(2) + 5x + 6](https://img.qammunity.org/2020/formulas/mathematics/middle-school/waj8ucxkosppbo0cklhqg6h8zxclw64qwu.png)
To understand how to plug it into the formula we need to know what each term represents.
![a {x}^(2) + bx + c](https://img.qammunity.org/2020/formulas/mathematics/middle-school/lzuctfy2qlheqwp29q3t4hox3bmqwves7b.png)
So the equation above would be put into the formula like this.
![x = \frac{ - 5± \sqrt{ {5}^(2) - 4(1)(6) } }{2(1)}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/up96faz7edwwq8725w672i5aao413jssn9.png)
Then we would solve
![( - 5± √(25 - 24) )/(2) \\ \\ = ( -5±1)/(2)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/112k1fjs03y9vij0a8jbd7o0urjt4b4pbu.png)
Now, the equation will branch off into one that solves when addition and one when subtraction.
![( - 5 + 1)/(2) = ( - 4)/(2) = - 2 \\ \\ ( - 5 - 1)/(2) = ( - 6)/(2) = - 3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/4f1mginby310pv4ox37epj8schblxkldkm.png)
So x={-3, -2} (-3 and -2)