2x + 7y = 14 and x + y = 2. Find the value of x and y which satisfy both equations.

There are 2 ways to solve simultaneous equations which are by substitution or elimination. In this example you can use both but elimination is simpler. So we have 2x + 7y = 14 and x + y = 2. To use elimination we either have to have the same number of x’s in both equations or the same number of y’s in the equation. In this case it is easier to use x. So 2x + 7y = 14 and we multiply x + y = 2 by 2 to give 2x + 2y = 4. We can then subtract the 2nd from the 1st to give 5y = 10 therefore y = 2 and so x = 0.