Working with the general equation of a straight line, 𝑦 = 𝑚𝑥 + 𝑐, use the interactive activity to see what a graph looks like when plotted. Select values for 𝑚, the gradient, and ...

Horizontal lines have a gradient of 0 and equations like y = 2. To work out a gradient, use the scales of the axes and find how many units you go up or down for each unit you move right.