IGCSE MATHS
posted by Anonymous .
A firm selling CDs finds that the number sold (N thousand) is related to the price (£P) by the formula 6P + N = 90.
(1) Draw the graph of N against P for 0 < N < 90 (the vertical axis should be the P axis,
and the horizontal axis should be the N axis).
(2) Use your graph to find the price when 30 000 CDs are sold.
(3) Use your graph to find the number sold if the price of a CD is set at £8.
(4) Use your graph to find the price if 90 000 CDs are sold. Is this a sensible value?

I'm not a math teacher by any means, but have you actually read what you posted?
This assignment involves drawing a graph ... which cannot be done on this website. Sorry.