The scale on the left graph is inappropriate. The numbers go up higher than necessary on both axes. This means the points are squashed into a small part of the graph area and are difficult to read ...

l.\) The gradient shows the cost per litre. Petrol costs £1.15 per litre. The graph crosses the vertical axis at (0, 0). This is known as the intercept. It shows that if you buy 0 litres ...