25 in total what do you mean
        
             
        
        
        
In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value with respect to a change in its argument.
 
        
             
        
        
        
If you are looking for the sales tax then you take 89.75 times .075 this will give you 6.73 now you just add 6.73 to 89.75 and you get..
sales tax = $96.48
but if you are looking for the %off you are going to do 89.75 minus 6.73 and you will get....
%off= $83.02
        
             
        
        
        
Step-by-step explanation:  
In order to find the better buy, we must find the cheaper unit price or price per gallon.  To find the price per gallon, divide the cost by the number of gallons.
Mary
Mary bought 4 gallons for $11.
The price is $11 and the gallons are 4.
Jill
Jill bought 2.5 gallons for $7.25
The price is $7.25 and the gallons are 2.5
Better buy
Mary paid $2.75 per gallon and Jill paid $2.90 per gallon. 2.75 is less than 2.90, so Mary had the better buy.
 
        
             
        
        
        
Answer:
18.11 miles per gallon
Step-by-step explanation:
Get the miles traveled from the trip odometer, or subtract the original odometer reading from the new one.
Divide the miles traveled by the amount of gallons it took to refill the tank. The result will be your car’s average miles per gallon yield for that driving period.
44,895-44,587 = 308 miles 
308/17 = 18.11