📈 Lines and slope: y = mx + b

Unit 2 · Algebra & data · 10 min

In y = mx + b, m is the slope (how much y changes when x grows by 1) and b is the intercept (where the line crosses the y-axis). Positive slope goes up, negative goes down, zero is flat.

Words in this lesson

• 斜率 (xiélǜ) — slope
• 直线 (zhíxiàn) — straight line
• 方程 (fāngchéng) — equation

Drag the line in the simulation and watch m and b change.

Project: Log how many minutes you walk each day for a week, plot it on grid paper and see whether the points roughly form a line.