Why do you need simultaneous equations?

This is an example of a simultaneous equation - 2X + Y = 5X + 3Y = 10 You can think of X and Y as apples and oranges from a market. You know that if you buy 2 apples and 1 orange it cost £5, but this doesn’t tell you how much each apple and orange costs. So if you know that 1 apple and 3 oranges costs £10 you can use simulaneous equations to work out how much one apple and one orange costs. 2X + Y = 5X + 3Y = 10 Y = 5 - 2X X + 3(5-2X) = 10 X + 15 - 6X = 10 -5X = - 5X = 1 (each apple costs £1) then you can use this to work out how much an orange costs...2X + Y = 5 2 + Y = 5Y = 3 (each orange costs £3)