On the GED Mathematical Reasoning test, quadratic equation problems will be pretty straightforward and simple, as the equations will contain only one variable. To solve quadratic equations in one variable, you have three options:
Factor the quadratic.
Complete the square.
Use the quadratic formula.
Regardless of which option you choose, the ultimate goal is to isolate the variable x (or whatever it happens to be) and solve for it.
When you're taking the test, you can click "Formula Sheet" in the upper-left corner of the screen to access a pop-up window that contains the quadratic formula.
The following practice questions ask you to solve in two ways: by factoring the quadratic and by using the quadratic formula.
Practice questions
Solve for x in the equation x2 – 5x + 6.
Solve for x in the equation x2 + 4x = 5.
Answers and explanations
The solution is (3, 2).
The two values of x that make the left side of the equation equal to 0 are 3 and 2, commonly presented as (3, 2).
The solution is (1, –5).