Question

It takes Lynn 4 hours to drive to her grandmothers house she. has already driven 2 1/2 Hours.Which of the following equations can be used to find the amount of time she has left to drive

Answer 1

`\text{Answer : x + 2}(1)/(2)\text{ = 4}`

Let the total number of hours Lynn would drive to her grandmother house be 4

She has already driven 2 1/2 hours

Let x be the remaining hours

`\begin{gathered} \text{ Remaining hours + Hours driven already = total hours } \\ \text{ Remaining hours = x} \\ \text{ Hours driven = x} \\ \text{Total hours = 4} \\ x\text{ + 2}(1)/(2)\text{ = 4} \end{gathered}`
`\begin{gathered} To\text{ calculate how many hours left to drive} \\ \text{Firstly, convert the mixed fraction to an improper fraction} \\ 2(1)/(2)\text{ = }\frac{2\text{ x 2 + 1}}{2} \\ =\text{ }(5)/(2) \\ \text{Hence, the equation becomes} \\ x\text{ + }(5)/(2)\text{ = 4} \\ x\text{ = 4 - }(5)/(2) \\ \text{Common denominator is 2} \\ x\text{ = }\frac{2\text{ x 4 - 5}}{2} \\ x\text{ = }\frac{8\text{ - 5}}{2} \\ =\text{ }(3)/(2) \\ =\text{ 1}(1)/(2) \end{gathered}`

She has 1 1/2 hours left to drive