3 teas and 2 coffees have a total cost of £7.80 5 teas and 4 coffees have a total cost of £14.20 Work out the cost of one tea and the cost of one coffee.
3t + 2c = 7.80 ---> x2 to get 6t + 4c = 15.605t + 4c = 14.20 6t + 4c = 15.60-- 5t + 4c = 14.20= 1t = 1.40If t = 1.40 substitute t in to the equation to get:(3 x 1.40) + 2c = 7.80 ---> 2c = 3.60 --> c = £1.80