Answer:
14 gallons of a gas more will she need to travel 240 miles.
Explanation:
Proportion states that the two fractions or ratios are equal.
Let x represents the more gallons will she need to travel 240 miles.
As per the statement:
12 gallons of gas to travel 144 miles. Six gallons in the tank.
Then;
By definition of proportion:
![(12)/(144) = (x+6)/(240)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/hjvh188k0jxkam9rlvg141pzukvpssgvzc.png)
Multiply 240 to both sides of an equation we have;
![(12)/(144) * 240 = x+6](https://img.qammunity.org/2020/formulas/mathematics/middle-school/1s0rayifnyaqwr3uuveuez78km9kuo97g6.png)
Simplify:
![20 = x+6](https://img.qammunity.org/2020/formulas/mathematics/middle-school/t4gl3iyskdpgigx15j6eh1926c6dai3kql.png)
Subtract 6 from both sides we get;
![14 = x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gubu5mnie5ybkcnl3aw1u57yaqol9d90by.png)
Therefore, 14 gallons of a gas more will she need to travel 240 miles.