Slope

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Slope

by beater » Mon Sep 22, 2008 12:27 pm
In the xy-plane, the line with equation ax + by + c = 0, where abc ≠ 0, has slope 2/3 . What is the value of b?
(1) a = 4
(2) c = −6
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by csandeepreddy » Mon Sep 22, 2008 1:59 pm
ax+by+ c = 0 can be written as y=(-a/b)x -(c/b)

equation for a line is y = mx +c where m is the slope and c is the constant

Thus implying slope = m = 2/3 = -a/b

According to statement 1, if a = 4
2/3 = -4/b => b = -6

statement 2 is in INSUFF because it does not give us anything to work with to get a or b.

So IMO A

Whats the OA?

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by beater » Mon Sep 22, 2008 2:01 pm
Perfect! OA - A.

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Re: Slope

by pradeepss » Mon Sep 22, 2008 4:28 pm
beater wrote:In the xy-plane, the line with equation ax + by + c = 0, where abc ≠ 0, has slope 2/3 . What is the value of b?
(1) a = 4
(2) c = −6

this is DS problem, posted in wrong section
Target 700 and HAAS

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by beater » Mon Sep 22, 2008 4:29 pm
Sorry!

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by Abdulla » Sun Dec 07, 2008 6:55 pm
csandeepreddy wrote:ax+by+ c = 0 can be written as y=(-a/b)x -(c/b)

equation for a line is y = mx +c where m is the slope and c is the constant

Thus implying slope = m = 2/3 = -a/b

According to statement 1, if a = 4
2/3 = -4/b => b = -6

statement 2 is in INSUFF because it does not give us anything to work with to get a or b.

So IMO A


Whats the OA?
Why we don't use the information the slope 2/3 = -a/b in the second statement, so we get y= -a/b x - c/b => -a/b = 2/3 and c= -6, so in that case we can slove for y ? I know I'm wrong but why ???
Abdulla