If your car gets 26 miles per gallon how much does it cost to drive 420 miles when gas is $2.80 per gallon

$45.22

Step-by-step explanation:

The number of miles per gallon can be represented by the ratio:

Since we know the unit rate of 26 miles per gallon of gas, we can set up a proportion, or equivalent ratios, to find the number of gallons needed for 420 miles:

, where 'x' is the number of gallons of gas

cross-multiply and divide:  26x = 420 or x ≈ 16.15 gallons

If gas is $2.80 per gallon, take the total number of gallons needed and multiply by $2.80:

16.15 x $2.80 = $45.22

The expression here is:

8x + 12y

x represents the number of hours of walking her neighbor's dog

y represents the number of hours of babysitting