Stage 21 · Linear Functions

21.5.3 Where Two Lines Cross and the System of Equations

21.5 Linear Functions Tie Together Equations and Inequalities

Point 3 of 5

21.5.3 Where Two Lines Cross and the System of Equations

Core idea

The point where two lines cross satisfies both equations at once, so the crossing's coordinates are the system's shared solution.

Module goal. Use the lens of the straight line to unify linear equations and inequalities, turning algebraic solving into "reading heights off the graph."
eastmath.com · 21.5 Linear Functions Tie Together Equations and Inequalities · 21.5.3 Where Two Lines Cross and the System of Equations