Alana and petra go to a used book sale, where every book is the same price. alana buys 4 books and petra buys 2 books. they run into their friend angus, who really loves to read, and discover that he has bought 16 books. angus received a $15 discount, but he still spent $5 more than alana and petra combined. how much does one book cost? $2.00 $24.50 $1.00 $2.50

A book cost $2.00

Step-by-step explanation: Given the no of books purchased by

Alana =4          Petra =2       Angus = 16

So

The total price of 4 books of Alana =4x$

Total price for Petra = 2x$

Total price of Alana and Petra =4x+2x

=6x$

Total price for Angus = 16x$

But given Angus received a discount  of $15

So price post discount = 16x- 15

According to the question

16x-15 = 6x +5

Adding 15 both sides

16x +15-15 = 6x + 5+15

16x= 6x+20

Subtracting 6x both sides

16x - 6x = 6x - 6x + 20

10x = 20

i.e x=2

Cost of one book = $2

isaiah walks 3 miles due north, turns and then 5 miles due east. how far is he from his starting point?

a^2 + b^2 = c^2

let c = distance from starting point.

(3)^2 + (5)^2 = c^2

9 + 25 = c^2

34 = c^2

sqrt{34} = sqrt{c^2}

sqrt{34} = c