Can you answer this quickly?

Question

You buy x bottles of soda for $1.50 using a gift card that you got as a reward for getting good grades on your last report card. Your gift card’s original balance was $15. The function 

f(x)=$15-$1.50x represents the amount of money you have left on the card after your purchase. What is the domain of the function? Explain your reasoning.

Answer 1

The domain of the function is the range of possible x values for our function.

Let's look at our function:

f(x)=$15-$1.50x

Remember that x is the number of soda bottles you bought. Well, the smallest possible value for x is 0. Any smaller would be a negative number, and you can't buy negative soda bottles.

Now let's find the maximum value of x. Since x is the number of soda bottles, then the maximum x value is just the maximum number of soda bottles we can buy. If we have $15 and each bottle costs $1.50, then the most we can buy is 10 bottles.

So our range is 0 to 10. We express range using brackets, so we write the answer like this:

range of x = [0, 10]

I hope this helps!

Answer 2

Your domain is $15.......................