Alana and petra go to a used book sale, where every book is the same price. alana buys 5 books and petra buys 4 books. they run into their friend angus, who really loves to read, and discover that he has bought 19 books. angus received a $10.00 discount, but he still spent $7.50 more than alana and petra combined. how much does one book cost?

7(x - 2) = 3(x + 4) solve the following equation. then enter your answer in the space provided using mixed number format.

Martha has a deck of cards. she has lost some of the cards, and now the deck only contains nine spades, eleven diamonds, eight clubs, and twelve hearts. martha predicts that whenever she draws a card from the deck without looking, she will draw a club one-fifth of the time. which activity would best allow martha to test her prediction? a. randomly draw a card from the box and see if it is a club. b. randomly draw a card. then, continue to draw another card until all eight clubs are drawn. c. randomly draw and replace a card 120 times. then, observe how close to 30 times a club is drawn. d. randomly draw and replace a card 100 times. then, observe how close to 20 times a club is drawn.

Aright triangle has an area of 21 m2. the dimensions of the triangle are increased by a scale factor of 4. what is the area of the new triangle