Simultaneous equations like 𝒚 = 2𝒙 - 1 and 𝒚 = 𝒙 + 1 can be represented graphically. To solve the equations graphically, the two lines 𝒚 = 𝒙 + 1 and 𝒚 = 2𝒙 - 1 are drawn on the same diagram.

Be careful to note what a GCSE question is asking. If it states ‘solve algebraically’ then you must do so. To find solutions from graphs, look for the point where the two graphs cross one another.

Grade school math students are likely familiar with teachers admonishing them not to just guess the answer to a problem. But a new proof establishes that, in fact, the right kind of guessing is ...