Stage 21 · Linear Functions

21.5.1 The Line's Crossing of the x-Axis Is the Equation's Solution

21.5 Linear Functions Tie Together Equations and Inequalities

Point 1 of 5

21.5.1 The Line's Crossing of the x-Axis Is the Equation's Solution

Core idea

The instant the line touches the x-axis, y=0, and the x there is exactly the solution of the equation kx+b=0.

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 · 21.5.1 The Line's Crossing of the x-Axis Is the Equation's Solution