How do I solve simultaneous equations?

2x + y = 7

3x - y = 8

You cannot find x and y using only one equations, but using both you can! So first you have use algebra to make both equations = y. Try this for the first equation by rearranging it.

This gives  y =7 - 2x

Now again for the second equation.

This gives y = 3x - 8

Now, because we can make these two equations equal, because they are both equal to y!

This gives 7 - 2x = 3x - 8

Now solve for x.

This gives 15 = 5x, so x = 15/5 = 3

Now that we know x, all we have to do it put in the value of x into one of the equations and solve it to get y!

y = 7 - 2x = 7 - 2*3 = 7 -6

y= 1 !