For N photos (N>50) you will pay £1000 for the 50 first photos and there will be (N-50) additional photos at £12 each.
The total cost is 1000+12(N-50)
A wedding photographer offers a package for £1000, for an album of 50 photos. Additional hpotos are charged at £12 each.
Write down the additional cost, in pounds, for N photos (wwhere N>50). Hence show that the total cost C, in pounds, for N phons is given by the formula C= 400 +12N
Thanks for your help