# ASVAB Mathematics Knowledge Practice: Quadratic Equations

When you run into a problem on the Mathematics Knowledge subtest on the ASVAB that deals with quadratic equations, you can use different ways to solve it: by factoring, completing the square, or using the quadratic formula.

The quadratic formula for equations in the form of ax2 + bx + c = 0 looks like this:

## Practice questions

- Express as a quadratic equation: 2
*x*^{2}– 8*x*– 4 = 3*x*–*x*^{2 }**A.***x*^{2}– 11*x*– 4 = 0

**B.**3*x*^{2}– 11*x*– 4 = 0

**C.**3*x*^{2}– 5*x*– 4 = 0

**D.**3*x*^{2}– 11*x*– 3 = 0 - Solve for
*x*:*x*^{2}– 3*x*= 0

## Answers and explanations

- The correct answer is
**Choice (B).**A quadratic equation has an

*x*^{2}term. When the equation is in standard form, both sides equal 0. Put all the terms on the same side, set the other side equal to 0, and combine like terms: - The correct answer is
**Choice (A).**A quadratic equation’s standard form is

*ax*^{2}+*bx*+*c*= 0. Although this equation shows only two terms,*x*^{2}and –3*x*, it’s still quadratic because there’s an*x*^{2}term (you can assume*c*= 0).Solve this quadratic equation by factoring:

Set each factor equal to 0; then solve:

The solutions are

*x*= 0 and*x*= 3.