SAT Math Practice
Linear Equations in Two Variables

Work with equations of the form Ax + By = C, including finding intercepts and interpreting graphs of lines.

26 original linear equations in two variables questions in the SAT Ranker bank, with instant scoring and an Elo-based rank once you sign up. Below are a few free samples with full explanations.

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Sample question 1 · easy

A line is defined by the equation 7x + 6y = 42. What is the line's x-intercept (the x-value where y = 0)?

6
7
42
-6

Setting y = 0 leaves 7x = 42. The answer is 6. 7 finds the y-intercept instead, by setting x to 0; 42 stops at 42 without dividing by the coefficient; -6 drops a sign when rearranging.

Sample question 2 · easy

A line is defined by the equation 7x + 11y = 77. What is the line's x-intercept (the x-value where y = 0)?

11
7
77
-11

Setting y = 0 leaves 7x = 77. The answer is 11. 7 finds the y-intercept instead, by setting x to 0; 77 stops at 77 without dividing by the coefficient; -11 drops a sign when rearranging.

Sample question 3 · easy

A line is defined by the equation 8x + 6y = 72. What is the line's y-intercept (the y-value where x = 0)?

12
9
72
-12

Setting x = 0 leaves 6y = 72. The answer is 12. 9 finds the x-intercept instead, by setting y to 0; 72 stops at 72 without dividing by the coefficient; -12 drops a sign when rearranging.

Sample question 4 · easy

A line is defined by the equation 3x + 7y = 21. What is the line's y-intercept (the y-value where x = 0)?

3
7
21
-3

Setting x = 0 leaves 7y = 21. The answer is 3. 7 finds the x-intercept instead, by setting y to 0; 21 stops at 21 without dividing by the coefficient; -3 drops a sign when rearranging.

Sample question 5 · easy

A line in the xy-plane passes through the point (0, 4) and has a slope of 3. What is the equation of the line?

y = 3x − 4
y = 4x + 3
y = 3x + 4
y = x + 4

In slope-intercept form y = mx + b, the slope m is 3 and the y-intercept b is 4 (the point where x = 0), giving y = 3x + 4. Choice y = 4x + 3 swaps the slope and intercept.

More topics
SAT Math skills
Linear Equations in One VariableLinear FunctionsLinear InequalitiesSystems of Linear EquationsEquivalent ExpressionsNonlinear Equations and SystemsNonlinear FunctionsRatios, Rates, Proportions, and UnitsPercentagesOne-Variable DataTwo-Variable DataProbabilitySample Statistics and Margin of ErrorEvaluating Statistical ClaimsRight Triangles and TrigonometryCirclesArea and VolumeLines, Angles, and Triangles