Question

The cost of a gallon of gasoline g is $3.25 less than 2 times the cost of a gallon diesel d. If a gasoline cost $3.95, what is the cost of s gallon of diesel? Write an equation and solve

Answer 1

2(cost of gallon of diesel) - $3.25 = (cost of gallon of gas)
This can be written down as 2d - 3.25 = 3.95, which is provided in the text.
If you switch sides then you get 3.95 + 3.25 = 2d, which is then 7.20 = 2d, or 3.60 = d.

Now that we have the price of a gallon of Diesel and you can check it buy just putting all the numbers in the equation.