80 CHAPTER 2 Fractions Solve the following application problems. 18. Becky Finnerty, a pastry chef. used 235 pounds of powdered sugar for one recipe, 18. 34 5 pounds powdered sugar for another recipe, and 17 pounds of powdered sugar for a third recipe. If Finnerty started with two 50-pound sacks of powdered sugar, find the amount of powdered sugar remaining. [2.3] 19. Rhonda Goedeker received her Social Security check of $1275. After paying $ of this 19. amount for rent, she paid ? of the remaining amount for food, utilities, and transportation. How much money does she have left? 20. A painting contractor arrived at a 6-unit apartment complex with 147 - gallons of paint. 20 If his crew sprayed 68 - gallons on the interior walls, rolled 37 : gallons on the masonry exterior, and brushed S gallons on the window trim, find the number of gallons of paint remaining. [2.3] 21. A pizza restaurant has 1000 ounces of mozzarella cheese in inventory. Find the number of 21. regular pizzas that can be made if each uses 8, ounces of mozzarella cheese, Find the num- ber of ounces of cheese remaining. Convert the following decimals to fractions. [2.5] 22. 625 = 23. .82 -2.2 Subtracting fractions 1. Find the LCD. 1 15 8 15 - 8 7 2. Rewrite fractions using the LCD. 3 24 24 24 24 3. Keep the LCD as denominator and subtract numerator. 4. Reduce to lowest terms. 2.3 Adding mixed numbers 2 8 1. Find the LCD, then add fractions and reduce. 12 LCD = 12 2. Add whole numbers. + 12 3. Combine the sums of whole numbers and fractions. 3 12 2.3 Subtracting mixed numbers 24 1. Find the LCD and subtract fractions, LCD = 24 borrowing if necessary. 3 2. Subtract whole numbers. 12 24 3. Combine the differences of whole numbers and 13 fractions. 2.4 Multiplying proper fractions 2 X 1. Multiply numerators and multiply denominators. 2. Reduce the answer to lowest terms if cancelling was not done. 2.4 Multiplying mixed numbers 1. Change mixed numbers to improper fractions. 2. Cancel if possible. 3. Multiply fractions. 16 Always reduce to lowest terms. 2.4 Dividing proper fractions 25 15 Invert the divisor, multiply as proper fractions, and reduce 36 18 36 the answer to lowest terms. 2.4 Dividing mixed numbers 32 12 3: + 2 Change mixed numbers to improper fractions, Invert the 12 divisor, cancel if possible, and then multiply fractions. 40 13 27 27 2.5 Converting decimals to fractions Convert .47 to a fraction. Think of the decimal as being written in words and write Think of .47 as "forty-seven hundredths." in fraction form. Reduce to lowest terms. Then write as 100