Digital SAT · Math
Equivalent Expressions on the Digital SAT: All Question Types
Equivalent Expressions asks you to rewrite an expression in a different but equal form: factoring, expanding, combining like terms, or simplifying a rational or radical expression. There is no equation to solve, only a transformation to carry out correctly. Because the choices are all expressions, a fast check is to substitute a convenient number into the original and each option and keep the ones that match, which the built-in Desmos calculator makes quick. This is an Advanced Math skill that appears regularly. The common errors are a sign slip when expanding, or stopping at a form that is close but not fully simplified. Deciding what form the question wants, factored, expanded, or reduced, before manipulating keeps the work aimed at the right target.
College Board skill: Advanced Math: Equivalent expressions
How Equivalent Expressions is tested
- how often it appears
- ~4 per test how often it appears
- typical difficulty
- Medium typical difficulty
- practice questions in our bank
- 157 practice questions in our bank
Rewrite in a legal form
Factor, expand, or combine to reach an equivalent form. When stuck, plug in a number to test which choice matches.
Frequency and difficulty come from this skill's questions across our assembled full-length Digital SAT forms; the practice count is how many drills of these types are in our bank.
2 question types in Equivalent Expressions
These ask which choice is equal to a given expression.
A literal equation uses letters in place of numbers, and you are asked to rewrite it to solve for a different variable.
Common questions
How do I check if two expressions are equivalent?
Substitute a convenient number for the variable into both and compare. If they match for a couple of values, they are equivalent. Desmos evaluates both instantly, which makes this a fast elimination method.
Is there an equation to solve in these questions?
No. Equivalent expression questions ask only for a rewrite, so you factor, expand, or simplify rather than solve. Treating them like equations wastes time on a step that is not there.
What causes the most errors here?
Sign mistakes when expanding, and stopping at a partially simplified form. Deciding whether the target is factored, expanded, or fully reduced before you start keeps the manipulation on track.
Practice Equivalent Expressions the way it is tested
Start with the free 16-question diagnostic, then drill any of these types with step-by-step reasoning.