Question: A firm has assessed that sales of its products are linked to the price it charges:
Q = 100 - 5P
where Q is sales (in 000s of units) and P is the price charged in £s per unit sold.
Draw a graph of this equation, known as a demand equation, and from the graph determine the following:
(a) sales when the firm charges a price of £7
(b) the price that was charged if the firm sold 40 000 units.