On a website selling books, three paperback books and five hardcover books cost $80.10, and seven paperback books and four hardcover books cost $100.65. what is the total cost of one paperback and one hardcover book?

Let us represent

Paperback books = p

Hardcover books = h

Three paperback books and five hardcover books cost $80.10

3p + 5h = 80.10Equation 1

Seven paperback books and four hardcover books cost $100.65

7p + 4h = 100.65Equation 2

Step 1

We have to find the cost of each paperback and hardcover book. We do this using the Elimination Method.

3p + 5h = 80.10Equation 1

7p + 4h = 100.65Equation 2

Multiply Equation 1 by 4 and Equation 2 by 5 to eliminate h

12p + 20h = 320.4Equation 3

35p + 20h = 503.25Equation 4

We subtract Equation 3 from Equation 4

23p = 182.85

We divide both sides by 23

23p/23 = 182.85/23

p = 7.95

The cost of one paperback book is $7.95

We solve for h, the cost of one hardback book by substituting 7.95 in Equation 1

3p + 5h = 80.10Equation 1

3(7.95) + 5h = 80.10

23.85 + 5h = 80.10

5h = 80.10 - 23.85

5h = 56.25

We divide both sides by 5

5h/5 = 56.25/5

h = 11.25

The cost of one hardback book is $11.25

Step 2

The cost of one paperback book is $7.95

The cost of one hardback book is $11.25

The total cost of one paperback and one hardcover book is

$7.95 + $11.25 = $19.20

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with btw u said 100pts but it clearly says

i answerd and just got 10pts

no hate

irrational, then, just means all the numbers that aren't rational. every integer is a rational number, since each integer n can be written in the form n/1. however, numbers like 1/2, 45454737/2424242, and -3/7 are also rational, since they are fractions whose numerator and denominator are integers.

step-by-step explanation: