Multiply and Divide Fractions

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Multiply and Divide Fractions
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Multiply and Divide Fractions

• Much easier than add subtract
• Reciprocal
• Flip the fraction over
• If not a fraction, then make it one
• Multiply Steps
• Multiply the numerators ? New numerator
• Multiply the denominators ? New denominator
• Reduce

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Examples

• (3/8)(4/9)
• (-3/4)(8/15)
• (5/x)(8/y)
• 3(5/8)

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Do It

• (c/9)(d/7)
• 8/7 (11)
• Evaluate xy when x (-4/5) y (6/7)

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Short-Cut

• Reducing before you multiply
• The rule Anything in the top with anything in
  the bottom
• Examples
• (3/8)(4/9)
• (-3/4)(8/15)
• (-5/9)(-12)
• (5/6)(18/25)(5/9)

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Try and Try again

• (-1/3) ( -5/12) (8/15)
• Find the product of (8/9) and 6
• 3(6/7) times 2(4/9)
• Evaluate zpy when z 5(1/8) and p 2/3 and y
  1 and t 49/7

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Dividing Fractions

• Make them easy
• How? Turn them into a multiplication problem
• How? Multiply by the reciprocal. Flip the second
  fraction over. Always the second fraction!

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Examples

• 2/5 divided by ¾
• -7/10 divided -14/15
• 2/3 divided by 11/4

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Divide!

• 5/6 divided by 10/27
• Find the quotient of 4 and -6/7
• 43/8 Divided by 31/2
• x/8 divided by y/6

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Homework

• 1-164 EOO
• No geometry!
• 165
• 166 ab