Respuesta :

cheesetoasty

Answer:

the original price of the book is $20

Step-by-step explanation:

sometimes in a question, they put things in the question that don't actually help us get to the answer. usually we ignore it, but i'm going to list them out just to help you a bit more.

Things that are useless:

  • his name is Jarred (his name could be gary, it doesn't affect us getting the answer)
  • he went to a bookstore (he could've gone to the library, it wont affect us getting to the answer)
  • the book is softcover (it could be any type of book, wont affect us getting to the answer)
  • the item is a book (it could be anything that he bought, wont affect us getting to the answer.)

Things that are helpful:

  • the book was on sale (helps us know that the price was reduced)
  • the book was on sale 10% (helps us know how much it was reduced by)
  • he spent $18 for the reduced price (helps us know how much he spent)

Ok, now that we know those, let's work on the question.

let b be the original book price

we need to find 10% so we have to use 90% (because 100 - 10 = 90)

if we needed to find 20% we would use 80% (because 100 - 20 = 80)

and so on.

  90% of b = 18    (90% of the og. book price equals 18)

90/100 × b = 18    (write a correct equation and make the percent a fraction)

    9/10 × b = 18    (simplify both sides of the equation)

         9 × b = 180  (multiply both sides of the equation to get rid of fraction)

               b = 20   (divide both sides of the equ. to get b by itself)

the original price of the book is $20

hope this helped :D

good luck my friend

- cheesetoasty