Ch12

#$&*

course Mth 158

9/29/11 at 10:30 A.M.

sorry I didn't get all my information in

If your solution to stated problem does not match the given solution, you should self-critique per instructions at http://vhcc2.vhcc.edu/dsmith/geninfo/labrynth_created_fall_05/levl1_22/levl2_81/file3_259.htm.

Your solution, attempt at solution:

If you are unable to attempt a solution, give a phrase-by-phrase interpretation of the problem along with a statement of what you do or do not understand about it. This response should be given, based on the work you did in completing the assignment, before you look at the given solution.

011. `* 11

* 1.2.13 \ 5. Explain, step by step, how you solved the equation z^2 - z - 6 = 0 using factoring.

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Your solution:

z^2 - z - 6 = 0

(z - 3)(z + 2) = 0

z = 3 , -2

confidence rating #$&*: 3

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Given Solution:

* * STUDENT SOLUTION WITH INSTRUCTOR COMMENT:

I factored this and came up with

(z + 2)(z - 3) = 0

Which broke down to

z + 2 = 0 and z - 3 = 0

This gave me the set {-2, 3}

-2 however, doesn't check out, but only 3 does, so the solution is:

z = 3

INSTRUCTOR COMMENT: It's good that you're checking out the solutions, because sometimes we get extraneous roots. But note that -2 also checks: (-2)^2 - (-2) - 6 = 4 + 2 - 6 = 0. **

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Self-critique (if necessary):

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Self-critique Rating:

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Question: * 1.2.14 (was 1.3.6). Explain how you solved the equation v^2+7v+6=0 by factoring.

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Your solution:

v^2 + 7v + 6 = 0

(v + 1)(v + 6) = 0

v = -1 , -3

confidence rating #$&*: 3

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Given Solution:

* * STUDENT SOLUTION:

v^2+7v+6=0. This factors into

(v + 1) (v + 6) = 0, which has solutions

v + 1 = 0 and v + 6 = 0, giving us

v = {-1, -6}

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Self-critique (if necessary):

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Self-critique Rating:

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Question: * 1.2.20 (was 1.3.12). Explain how you solved the equation x(x+4)=12 by factoring.

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Your solution:

x(x+4) = 12 Factors out to

x^2 + 4x - 12 = 0

(x - 2)(x + 6) = 0

x = (2 , -6)

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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Given Solution:

* * Starting with

x(x+4)=12 apply the Distributive Law to the left-hand side:

x^2 + 4x = 12 add -12 to both sides:

x^2 + 4x -12 = 0 factor:

(x - 2)(x + 6) = 0 apply the zero property:

(x - 2) = 0 or (x + 6) = 0 so that

x = {2 , -6} **

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Self-critique (if necessary):

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Self-critique Rating: