value M

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value M

by mariah » Fri Nov 13, 2009 1:41 pm
If /M+4/=2, what is the value of M? /module/
(1) M<0 (2) M^2+8M+12=0

[spoiler]imo D
OA E[/spoiler]
Source: — Data Sufficiency |

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by grockit_jake » Fri Nov 13, 2009 2:21 pm
If /M+4/=2, what is the value of M? /module/
(1) M<0
(2) M^2+8M+12=0

The stimulus can be solved for M = -2 or M = -6

(1) does not clarify if it's M = -2 or M = -6 since both are negative.

(2) M^2+8M+12=0 can be factored into:

(M+2)(M+6) = 0, which also has the two solutions M = -2 and M = -6.

Even with both we cannot determine which answer is correct.
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by mariah » Sat Nov 14, 2009 12:40 am
:oops: how did i miss that! i guess i was sleeping...