Any equation that can be rearranged into the form \(y = mx + c\), will have a straight line graph. \(m\) is the gradient, or steepness of the graph, and \(c\) is the \(y\)-intercept, or where the line ...

All real-life graphs can be used to estimate or read-off values. The actual meaning of the values will depend on the labels and units shown on each axis. Sometimes: This graph shows the cost of petrol ...