5-Minute Check on Chapter 2 Transparency 3-1 5-Minute Check on Chapter 2 Evaluate 42 - |x - 7| if x = -3 Find 4.1  (-0.5) Simplify each expression 3. 8(-2c + 5) + 9c 4. (36d – 18) / (-9) A bag of lollipops has 10 red, 15 green, and 15 yellow lollipops. If one is chosen at random, what is the probability that it is not green? Which of the following is a true statement Standardized Test Practice: A 8/4 < 4/8 B -4/8 < -8/4 C -4/8 > -8/4 D -4/8 > 4/8 Click the mouse button or press the Space Bar to display the answers.

Multiplying Rational Expressions Lesson 12-3 Multiplying Rational Expressions

Click the mouse button or press the Space Bar to display the answers. Transparency 3

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Objectives Multiply rational expressions Use dimensional analysis with multiplication

Vocabulary None new

Key Concept xxxxx

Example 1a Find Method 1: Divide by the greatest common factor after multiplying. Multiply the numerators. Multiply the denominators. The GCF is 98xyz. Simplify.

Example 1a cont Method 2 Divide the common factors before multiplying. Divide by common factors and z. 1 x 6 z 2 y 3 Multiply. Answer:

Example 1b Find Divide by common factors and r. Multiply. Answer: d 2 q 2 r 3 Multiply. Answer:

Example 2a Find Factor the numerator. The GCF is Simplify. Answer: x 2 1 x 2 Simplify. Answer:

Example 2b Find Factor. The GCF is 1 Multiply. Simplify. Answer:

Example 3 Space The velocity that a spacecraft must have in order to escape Earth’s gravitational pull is called the escape velocity. The escape velocity for a spacecraft leaving Earth is about 40,320 kilometers per hour. What is this speed in meters per second?

Example 3 cont 1120 10 1 Simplify. Multiply. Answer: The escape velocity is 11,200 meters per second.

Summary & Homework Summary: Homework: Finding common factors to simplify numbers Multiplying rational expressions is similar to multiplying rational numbers Homework: pg