Simultaneous Equations is an online exercise to use instead of a text book. The questions are presented one at a time in increasing order of difficulty. You must get the current question right before going on to the next. When you have answered 5 questions correctly you are given the option of printing a certificate or claiming a Transum Trophy to show your achievement. The certificate will show how many questions you have answered correctly so you might want to wait before you print until you have answered as many questions as possible.