Reteaching - RoweMathWiki

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Reteaching

11-5 Solving Rational Equations Solving rational equations uses the properties of simplifying rational expressions in an equation that solves for an unknown variable.

What is the the solution of

2 3 1   ? x 2x 4

2 3 1   ? x 2x 4

Solve

The denominators are x, 2x, and 4. The LCD is 4x.

2 3  1 4x     4x    x 2x  4

2  3  1 4x    4x    4x    x  2x   4

Multiply each side by 4x.

Distributive Property Simplify.

8+6= x

Add.

14 = x

Check your solution. For some rational equations, you may have to solve a quadratic equation after multiplying each side of the equation by the LCD. There may be more than one solution.

What is the the solution of 2 

2 4  ? x x2

2   4 x2  2    x2  2  x  x 

Solve

2  4 x 2 (2)  x 2    x 2  2   x x 

2x2 + 2x = 4 x2 + x = 2 x2 + x  2 = 0 (x + 2)(x  1) = 0 x+2=0

x1=0

x = 2 or

x=1

Multiply each side by the LCD, x2.

Distributive Property Simplify. Divide each side by 2. Collect terms on one side. Factor the quadratic expression. Zero-Product Property Solve for x.

Check your solutions.

Prentice Hall Algebra 1 • Teaching Resources Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.

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Name

Class

Date

Reteaching (continued)

11-5

Solving Rational Equations

Exercises Solve each equation. Check your solutions. 1.

1 2  3 x x

2.

4 6   10 2x 2x

3.

6 5  9 9b 3b

4.

1 5  8 20c 4c

6.

4 6  2 y y2

8.

2 4   2 z 1 z 1

5. 1 

2 –1  x x2

7. 2 x  1 

1 x2

9. Your sister can paint a room in 5 hours. Your dad can paint the same room in

1 hours. How long will it take your sister and your dad to paint the room if 2 they work together? 3

Solve each equation. Check your solutions. If there is no solution, write no solution.

10.

8 4  x 1 x 1

11.

6 2  x  x  12 x  4

12.

5 1 2 –  12 4 x 3x

13.

4x  1 6  x  x2 x–2

14.

5 1 5 x   7x 4 x

15.

6 4x 1  9( x  6) x6

2

Prentice Hall Algebra 1 • Teaching Resources Copyright © by Pearson Education, Inc., or its affiliates. All Rights Reserved.

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