Answer:
36
Step-by-step explanation:
first, see the formula in the attached picture.
now, by applying that formula we get :
the coefficient of the x7y2 is :
9C7 = 36 (you can either use a calculator or just the algebraic formula)
The equivalent equation is d=17+12.5
it simplifies to d=29.5
($3.91)(0.09) = $0.3519
$3.91 + 0.3519 = $4.2619 per gallon
if you're looking for the total expense next year:
($4.2619)(370 gallons) = $1,576.903