A set of simultaneous equations most commonly represents two lines on a graph, or perhaps a circle, with a line running through it. When you solve a set of simultaneous equations, its important to remember that what you are actually doing is finding the coordinates on the graph, in the case of two straight lines, where the two lines cross. There are two methods of solving simultaneous equations; by elimination or substitution. In the case above, only one of the equations (equation 2) contains an x, and a y, meaning there's no need to use elimination. Substituting equation 1 into equation 2 will leave us with the following: -> 1: x = 2, y = x + 5 - > Substitute 1 into 2: -> y = 2 + 5 = 7 -> Ans: x = 2, y = 7. This is a very basic example but aims to start helping one to spot when to use elimination, or substitution when solving simultaneous equations.