This problem cannot be done because it is not an equation meaning it does not have an “=“
yes it is correct
with parentheses you have to bring EVERYTHING INSIDE THE PARENTHESES to the given power but not if there are no parentheses
Let the difference between consecutive terms be D. If the middle term is 30, then the term before it is 30-D, and the term after it is 30+D. So the sum of these three terms would be (30-D) + 30 + (30+D) = 3*30.
Extending this sum to include all 11 terms centered around 30, we see that any addition of D is canceled by a balanced subtraction, leaving you with 11 copies of 30. So the value of the sum is 11*30 = 330.
answer
$962.50
set up equation
first, we want to find out how many gallons of gas she'll save a year
x1 = gallons for old car
x2 = gallons for new car
gallons saved = x1 - x2 since she uses more gallons with the old car with a lower miles per gallon
then, find how much she saves on gas by multiply the price per gallon (3.85) by gallons saved
price saved = gallons saved * price
price saved = (x1 - x2) * 3.85
gallons with old car
to find the number of gallons, we divide the number of miles (15000) by miles per gallon (24 for the old car)
x1 = 15000 / 24
x1 = 625
gallons with new car
use the same process as with the old car, but with 40 miles per gallon instead
x2 = 15000 / 40
x2 = 375
plug in values
price saved = (x1 - x2) * 3.85
price saved = (625 - 375) * 3.85
price saved = 250 * 3.85
price saved = $962.50