Using an equation to solve a word problem.
An equation may be used to model a situation. For example:
Question
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 hire the van for?
First we need to put this information into an equation.
\(x\) is the number of hours they hired the van for. This is what we have to find.
Their total bill will be £17 plus £6 times \(x\) hour.
We usually write this as \(6x + 17\).
\(6x + 17 = 59\)
Change side and change operation (\(+ 17\) on the left becomes \(- 17\) on the right):
\(6x = 59 - 17\)
\(6x = 42\)
Change side and change operation (\(\times 6\) on the left becomes \(÷ 6\) on the right):
\(x = 42 \div 6\)
\(x = 7\)
Therefore they hired the van for 7 hours.
