Linear Equations on the SAT

Linear equations and functions account for approximately 30% of SAT Math questions. They appear across both the calculator and no-calculator sections.

Key Forms of a Linear Equation

• Slope-intercept: y = mx + b (m = slope, b = y-intercept)
• Standard form: ax + by = c
• Point-slope: y − y₁ = m(x − x₁)

What SAT Tests

• Creating equations from word problems
• Solving systems of equations (substitution/elimination)
• Interpreting slope and intercept in context
• Recognising when a system has 0, 1, or infinite solutions

Quick Tip

For "no solution" systems, the lines are parallel (same slope, different intercept). For "infinite solutions", the equations are identical.