For quadratic equations that factor over the integers, factoring is often the fastest way to find the solution.
Here is a worksheet with a bunch of factorable quadratic equations. However, if you’re struggling with this, you’re probably struggling with the factoring part, so you should go back and review factoring here.
If the quadratic doesn’t factor, you can complete the square and take square roots of both sides to find the solution.
Here is a worksheet on completing the square to solve quadratics.
Finally, you can use the quadratic formula to solve quadratic equations as well. A lot of people prefer this way as it’s very mechanical and deterministic.
Here is a worksheet to practice using the quadratic formula.
A lot of times the part people struggle with when using the quadratic formula is simplifying the radical. Here is a quick video on a way to do that.
Here is a worksheet in case you need practice with the above method.