All you have to do is look at the graph. 5 gallons of gas is $8.80, let’s figure out how much one gallon is. 8.80/5=$1.76. 1.76•6=10.56 check 1.76•7=12.32 check Now let’s figure out how much 10 gallons of gas cost. 1.76•10=17.6 10 gallons of gas costs $17.60