Where do the lines meet?

SparkClass

Adjust each equation. Watch the graph, coordinates, and algebra update together.

CCSS 8.EE.C.8a–b

Coordinate plane

Auto-fit on

Control console

Line A y = 2x + 1

Slope · m₁ 2

y-intercept · b₁ 1

Line B y = −x + 7

Slope · m₂ −1

y-intercept · b₂ 7

Solution check

Unique solution

The lines meet at exactly one point.

x-value2

y-value5

Solve & substitute

Teacher notes

Learning goal: Connect the intersection of two graphs with the solution of a system, then verify that solution algebraically (8.EE.C.8a–b).

Suggested prompts:

Tip: Slope and intercept values move in half-unit steps. The plane rescales to keep key points visible.