Question 4 (nov.24th)

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Question 4 (nov.24th)

by bacali » Mon Nov 24, 2008 11:40 am
Q26:

In the xy-plane, the line with equation ax + by + c = 0, where abc ≠ 0, has slope 32. What is the value of b?
(1) a = 4
(2) c = −6


OA: A

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by jackcrystal » Mon Nov 24, 2008 2:03 pm
y = -(a/b)x -c

=> 32 = -a/b


I. plug value foe a and get b.

Suff

II. C has nothing to do with slop

not suff.

Hence

A

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by niraj_a » Mon Nov 24, 2008 2:05 pm
simple but dumb question - why wouldn't you divide c by b as well in the initial equation?

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by hwiya320 » Mon Nov 24, 2008 4:58 pm
niraj_a wrote:simple but dumb question - why wouldn't you divide c by b as well in the initial equation?
You will have to divide "C" by "B" in order to keep the original equation. Even if you were dividing C by B, you would still be able to determine what B is from -(a/b)x + c/b = x, because you're not looking for x or c, but working with slope = 32.

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by niraj_a » Tue Nov 25, 2008 5:59 am
gotcha now...cheers!