Question 896560
First set up your problem:
{{{270/6=675/x}}}

Next cross multiply:
{{{270*x=675*6}}}

Then simplify and solve for x:

{{{270*x=4050}}}
{{{x=4050/270}}}
{{{x=15}}}

So, she will use roughly 15 gallons of gas if she drives 675 miles.

-Alejandro