Solve these simultaneous equations. 2x + y = 18 x - y = 6

With simultaneous equations there is more than one unknown. First we’ll get one unknown on its own so we rearrange the bottom equation to get x on its own. By adding y to each side of the equation this leaves x = 6 + y. Now we can put this into the top equation to be 2(6 + y) + y =18. This can now be solved to find y. Expanding out of the brackets gives 12 + 2y + y =18. Collecting the ys gives 12 + 3y = 18. Subtract 12 from both sides leaves 3y =6 which gives y to be 2. Now we know y =2, we can put that in to one of the equations and get a value for x. The bottom equation would now read x – 2 = 6. Adding 2 to both sides now gives x = 8. Therefore the answer is x = 8, y = 2.