Find a common denominator between 1/4 and 1/9. The common denominator is 36. Multiply 1/4, 1 and 4, by 9. You get 9/36. Multiply 1/9, 1 and 9, by 4. You get 4/36. Add the two answers together. 9/36 + 4/36 = 13/36 Now subtract 36 by 13 to get 23. You get 23/36. This is the most simplified form. Ashley has 23/36 package of raisin left.
In this case if x<100 George will be losing money. So he will only earn a profit when he sells more than 100 DVDs. Essentially (x-100) represents his break-even point.