Jarred went to the bookstore, He bought a softcover book which was on sale for 10%
off. He spent $18 on the book, What was the original
price?

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:

Things that are helpful:

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

1/5x+9 2/5y+7

step-by-step explanation:

when functions are first introduced, you will probably have some simplistic "functions" and relations to deal with, usually being just sets of points. these won't be terribly useful or interesting functions and relations, but your text wants you to get the idea of what the domain and range of a function are. small sets of points are generally the simplest sorts of relations, so your book starts with those.

step-by-step explanation:

state the domain and range of the following relation. is the relation a function?

{(2, –3), (4, 6), (3, –1), (6, 6), (2, 3)}

the above list of points, being a relationship between certain x's and certain y's, is a relation. the domain is all the x-values, and the range is all the y-values. to give the domain and the range, i just list the values without duplication:

domain: {2, 3, 4, 6}

range: {–3, –1, 3, 6}

(it is customary to list these values in numerical order, but it is not required. sets are called "unordered lists", so you can list the numbers in any order you feel like. just don't duplicate: technically, repetitions are okay in sets, but most instructors would count off for this.)

while the given set does indeed represent a relation (because x's and y's are being related to each other), the set they gave me contains two points with the same x-value: (2, –3) and (2, 3). since x = 2 gives me two possible destinations (that is, two possible y-values), then this relation is not a function.

note that all i had to do to check whether the relation was a function was to look for duplicate x-values. if you find any duplicate x-values, then the different y-values mean that you do not have a function. remember: for a relation to be a function, each x-value has to go to one, and only one, y-value.

state the domain and range of the following relation. is the relation a function?

{(–3, 5), (–2, 5), (–1, 5), (0, 5), (1, 5), (2, 5)}

i'll just list the x-values for the domain and the y-values for the range: