Rudy worked hard all summer. Before school starts he decided to go shopping and spend some of his earnings. He spent one third o
f his money on a new shirt at Hot Fashions in the mall. He then went to Marvin's Music and bought a CD with one third of the money he had left. At Movies-to-go he spent one third of the money he now had on a video he wanted. He stopped one more time on his way home and bought a paperback at Bert's Book Shop with one third of his remaining money. Rudy arrived home with just $16.00 in his wallet. How much money did he have when he started out?
This is a constant problem. He kept on spending 1/3 of his money. The inverse number of 1/3 is 3. Basically the fraction flipped. So he spent 1/3 of his money 4 times. So we multiply 16*3*3*3*3. Multiply by 3 four times. 16*3 is 48. 48*3 is 144. 144*3 is 432. 432*3 is 1296. He started with 1296 dollars. If hes a kid hes rich.
A linear equation would be the best fit, but the last point (-1,-7) kinda messes it up. If the -7 would have been a -6 the line y=-2x-8 would fit perfectly.
