Determine the domain of the inverse function and find the inverse function.

now, the range for that equation is all real numbers, is a linear equation and therefore will pass the "vertical line test" and thus be a one-to-one function, and therefore will have an inverse function.

for a function that has an inverse function, the range of the original function is exactly the same as the domain for its inverse.  Therefore, if the range of that function is all real numbers, then the domain of its inverse is just that.

what's the inverse, well, let's do the switcharoo.



we are not solving for "h", because, well, is already solved for "h".

They are both correct.
By multiplying the original price of the book by 30%. Oscar is finding the amount of the discount. He then takes the discount off of the original price by subtraction. 28.50 * .30 = 8.55; 28.50-8.55 = 19.95; After he finds the new price he calculates the tax and adds it to the book price. 19.95 * .10 = 2.00 = $21.95
Instead of finding the amount of the discount, Kim found the amount she would have to pay after the 30% was subtracted from the 100%. This left 70% that had to be paid. 28.50 * .70 = 19.95; Then Kim knew that she had to pay this entire amount which was 100% plus another 10% for tax which is 110% so 19.95 * 1.10 = $ 21.95
Both Oscar and Kim got the same amount and they both had enough money to buy the book