dolphin
Get Started

SAT Math skill page

SAT Equivalent Expressions Practice

Recognize when two algebra expressions say the same thing in different forms.

Practice equivalent expressions in Dolphin SATPractice questions
10-16 min practice time3 questions on pageAdvanced Math
Practice time10-16 min
Question bank3 questions
Best forAdvanced Math

What this tests

What to know for this SAT skill

Dolphin question bank

Practice your skill

Question 1 of 3Easy
Which expression is equivalent to 3(x + 4)?
  1. 3x + 4
  2. 3x + 7
  3. 3x + 12
  4. x + 12
Show answer and solution
Correct answerC. 3x + 12

Solution walkthrough

  1. Distribute 3 to both terms: 3(x + 4) = 3x + 12.
Question 2 of 3Medium
Which expression is equivalent to 4x + 12?
  1. 4(x + 3)
  2. 4(x + 12)
  3. x(4 + 12)
  4. 12(x + 4)
Show answer and solution
Correct answerA. 4(x + 3)

Solution walkthrough

  1. Factor out the common factor 4: 4x + 12 = 4(x + 3).
Question 3 of 3Hard
If 2a + 2b = 18, what is the value of a + b?
  1. 6
  2. 8
  3. 9
  4. 18
Show answer and solution
Correct answerC. 9

Solution walkthrough

  1. Factor the left side: 2(a + b) = 18.
  2. Divide by 2 to get a + b = 9.

Avoid these traps

Common mistakes on this skill

Checking only one input value

Two expressions are equivalent only if they have the same value for every allowed input, not just one convenient test value.

Losing a negative sign while distributing

A factor outside parentheses multiplies every term inside, including each term following a minus sign.

Study plan

How to practice this skill in Dolphin

  1. Choose whether distribution, factoring, or combining like terms best exposes the structure.
  2. Rewrite one expression one operation at a time without changing its value.
  3. Verify the final form with a second method or more than one permitted input value.
Practice equivalent expressions in Dolphin SAT

Related practice

Build the surrounding skills

SAT Linear Equations PracticeSAT Quadratic Equations PracticeSAT Exponential Functions PracticeSAT Math skill hub

Skill cluster

Keep practicing SAT Math

SAT Math skill hubSAT Linear Equations PracticeSAT Systems of Equations PracticeSAT Linear Functions PracticeSAT Quadratic Equations PracticeSAT Percentages PracticeSAT Ratios and Proportions PracticeSAT Probability PracticeSAT Geometry PracticeSAT Right Triangles PracticeSAT Data Analysis PracticeSAT Circle Equations PracticeSAT Exponential Functions PracticeSAT Inequalities PracticeSAT Systems of Inequalities PracticeSAT Absolute Value Equations PracticeSAT Function Notation PracticeSAT Polynomials PracticeSAT Scatterplots PracticeSAT Mean and Median PracticeSAT Unit Conversions PracticeSAT Exponent Rules PracticeSAT Quadratic Word Problems PracticeSAT Systems Word Problems PracticeSAT Slope-Intercept Form PracticeSAT Area and Volume PracticeSAT Percent Change PracticeSAT Trigonometry PracticeSAT Rational Equations PracticeSAT Radical Equations PracticeSAT Conditional Probability PracticeSAT Sampling and Margin of Error PracticeSAT Statistical Claims PracticeSAT Reading and Writing Practice PagesDolphin SAT study guidesSAT score guides by college

FAQ

Questions about SAT Equivalent Expressions Practice

What makes two expressions equivalent?

They produce the same value for every input in their shared domain.

Can I prove equivalence by testing numbers?

Testing can catch an error, but algebraic rewriting is the reliable proof because one matching input is not sufficient.