The price of gas at Leon's gas station is $1.50 per litre. If a customer buys a minimum of 10 litres, a discount of $5 is applied. This can be modelled by the following function, L, which gives the total cost when buying a minimum of 10 litres at Leon's gas station. L(x) = 1.50x-5, x2 10 where x is the number of litres of gas that a customer buys. (a) Find the total cost of buying 40 litres of gas at Leon's gas station. (b) Find L(70). The price of gas at Erica's gas station is $1.30 per litre. A customer must buy a minimum of 10 litres of gas. The total cost at Erica's gas station is cheaper than Leon's gas station when x> k. (c) Find the minimum value of k.

Suppose the function f(x) = 9.09x represents the number of Chinese yuan equivalent to x U.S. dollars and the function g(y) = 0.10y represents the number of British pounds equivalent to y Chinese yuan. a. Write a composite function that represents the number of British pounds equivalent to x U.S. dollars. b. Find the value in British pounds of an item that costs 25 U.S. dollars. a. The composite function is (fog)(x) = (Simplify your answer. Round es as needed.) (gof)(x) (fog)(x)