On tuesday, you sold $2,889.32 in regular gas; on wednesday, you sold $2,996.42, and on thursday, you sold $3,435.53. if the price of regular gas was (to the nearest penny) $1.19 per gallon all week, how many gallons

Add the three amounts first.
$2,889.32 + $2,996.42 + $3,435.53 = $9321.27

Now divide the total amount of sales by the cost per gallon to find the number of gallons.

9321.27/1.19 = 7833

The total amount of regular gas sold on Tuesday, Wednesday, and Thursday was 7833 gallons.