Solve by Quadratic Formula
About this exercise
Solving a quadratic with the formula.
Example problems
A few of the problems this exercise asks. The printable worksheet holds ten fresh ones.
- Use the quadratic formula to solve: x² + 3x − 18 = 0
- Use the quadratic formula to solve: x² − 2x − 24 = 0
- Use the quadratic formula to solve: x² + 3x − 4 = 0
- Use the quadratic formula to solve: x² − 7x + 6 = 0
Try it yourself first — open a section below only if you get stuck.
How to solve it
Take minus b, plus or minus the square root of the discriminant, all over 2a.
Worked example
For x squared - 5x + 6, the roots come out as 3 and 2.
Common mistake
Dividing only part of the expression by 2a. The whole numerator is divided.