Question 198872
Since 45 miles is to 2 gallons of gas and 315 miles is to "x" gallons, this means we have the ratio: {{{45/2=315/x}}} 




{{{45/2=315/x}}} Start with the given ratio



{{{(45/2)*x=315}}} Multiply both sides by x



{{{45*x=315*2}}} Multiply both sides by 2



{{{45*x=630}}} Multiply



{{{x=630/45}}} Divide both sides by 45



{{{x=14}}} Simplify




So our answer is  {{{x=14}}} which means that it takes 14 gallons of gas to go 315 miles.