A linear graph is a straight line drawn from an equation. The equation y = mx + c holds two secrets: m sets how steep the line is (the slope), and c sets where it crosses the y-axis (the intercept). Change either and the whole line moves.
Straight-line graphs model everything from speed and cost to data trends — and they are the gateway to all of algebra and coordinate geometry.
How steep the line is — rise divided by run. A bigger m means a steeper line.
The y-value where the line crosses the y-axis (at x = 0).
A negative m makes the line fall from left to right instead of rising.
Any two distinct points fix exactly one straight line.
Increase m and the line tips up more steeply; change c and the whole line shifts up or down without changing its tilt.
Given two points, the slope is the change in y over the change in x, and the intercept is where the line would meet the y-axis.
m is the slope (rise ÷ run); c is the y-intercept — where the line crosses the y-axis.
Turn the concepts above into a skill — play the game and get instant feedback.