For example, the simultaneous equations \(3a + 2b = 17\) and \(4a - b = 30\) have no common coefficient as the coefficients of \(a\) are 3 and 4, and the coefficients of \(b\) are 2 and -1. Remember ...

Mr and Mrs Wallace hire a van for moving house. They see this advert in the local paper and decide to use this company. When they hand the van back, their bill comes to £59. How many hours did they ...