All lessons › Unit 5 · Advanced Math

Polynomial zeros and rational expressions

A zero of a polynomial is an x value that makes it equal 0, and it is where the graph crosses the x-axis. The Digital SAT Math section expects you to connect the equation, its factors and its graph.

This lesson shows how to find zeros from a factored form and from a graph. Then it covers rational expressions, which are fractions with x in them: how to cancel, combine them and spot values that are not allowed. A quiz after each part checks that you can move between factors, zeros and graphs.

In this lesson

• Zeros of polynomials
• Rational expressions