Solve the simultaneous equations: 2x + y = 12; x - y = 6

We add the two equations together (left-hand sides and right-hand sides separately). By doing this we get: 2x + y + (x - y) = 12 + 6. By rearranging and simplifying: 3x = 18.If we divide both sides by 3 we get: x = 6.By substituting the value of x into the second equation we get: 6 - y = 6 which makes y = 0.The solution is x = 6 and y = 0.

RD

Related Maths GCSE answers

All answers ▸

I want to buy 1 litre of milk. My options are to either buy 250ml bottles for £1 each or 500ml bottles for £1.50 each. Which is the cheapest way for me to buy 1 litre of milk?


What is the nth-term of this sequence? 29, 26, 23, 20, 17...


3/5 of a number is 162. what is the number?


A ball, dropped vertically, falls d metres in t seconds. d is directly proportional to the square of t. The ball drops 45 metres in the first 3 seconds. How far does the ball drop in the next 7 seconds?