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8.8 Mixed Expressions and Complex Fractions. CORD Math Mrs. Spitz Fall 2006. Objective. Simplify mixed expressions and complex fractions. Upcoming. 8.8 Friday 10/27 8.9 Monday 10/30 8.10 Tuesday/Wed Chapter 8 Review Wed/Thur Chapter 8 Test Friday. Assignment. Pgs. 336-337 #3-29 all.
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8.8 Mixed Expressions and Complex Fractions CORD Math Mrs. Spitz Fall 2006
Objective • Simplify mixed expressions and complex fractions.
Upcoming • 8.8 Friday 10/27 • 8.9 Monday 10/30 • 8.10 Tuesday/Wed • Chapter 8 Review Wed/Thur • Chapter 8 Test Friday
Assignment • Pgs. 336-337 #3-29 all
Introduction • Algebraic expressions such as are called mixed expressions. Changing mixed expressions to rational expression is similar to changing mixed numbers to improper fractions.
Ex. 1: Find ← Multiply by x2 + y2 representation of 1. ← Combine both 1st and 2nd terms over the common denominator x2 + y2. ← Distribute the 8 using distributive property. ← Combine like terms and simplify.
What if it has more than one fraction? • If a fraction has one or more fractions in the numerator or denominator, it is called a complex fraction. Some complex fractions are shown below:
Consider the complex fraction. To simplify this fraction, rewrite it as: and proceed as follows: Recall that to find the quotient, you multiply by 8/7, the reciprocal of 7/8.
Consider the complex fraction. To simplify this fraction, rewrite it as: and proceed as follows: Recall that to find the quotient, you multiply by d/c, the reciprocal of c/d.
Simplifying Complex Fractions Rule • Any complex fraction Where b ≠ 0, c ≠ 0, and d ≠ 0, may be expressed as:
Ex. 2: Simplify ← The LCD is xy for both the numerator and the denominator. ← Add to simplify the numerator and subtract to simplify the denominator. ← Multiply the numerator by the reciprocal of the denominator.
Ex. 2: Simplify ← Eliminate common factors.
Ex. 3: Simplify ← The LCD of the numerator is x + 4, and the LCD of the denominator is x – 3.
Ex. 3: Simplify ← FOIL the top and don’t forget to subtract the 1 and add the 48 on the bottom.
Ex. 3: Simplify ← Simplify by subtracting the 1 in the numerator and adding the 48 in the denominator.
Ex. 3: Simplify ← Multiply by the reciprocal. x2 + 8x +15 is a common factor that can be eliminated.
Ex. 3: Simplify ← Simplify
Ex. 4: Simplify ← The LCD of the numerator is x + 1, and the LCD of the denominator is x – 2.
Ex. 4: Simplify ← Distribute and subtract to simplify the numerator.
Ex. 4: Simplify ← Simplify
Ex. 4: Simplify ← Multiply by the reciprocal. ← x – 2 is the common factor which can be eliminated.