* Modulo Murder

by **gmattt** Wed Oct 08, 2008 5:29 pm

What is the value of │x + 7│?
(1) │x + 3│= 14
(2) (x + 2)^2 = 169

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

by **Chak De** Sat Nov 01, 2008 8:07 am

What is the value of │x + 7│?

(1) │x + 3│= 14

Case 1
X + 3 = 14
X = 11

X+7 = 18
│X + 7│=18

Case 1
X + 3 = -14
X = -17

X+7 = -10
│X + 7│=10

Not Sufficient

(2) (x + 2)^2 = 169

(X + 2)^2 - 169 = 0
(X + 2)^2 - 13^2 = 0
(X + 2 + 13)(X + 2 - 13) = 0 [ a^2 - b^2 = (a+b)(a-b) ]
(X + 15)(X - 11) = 0

Case 1
(X + 15) = 0
X = -15

X+7 = -8
│X + 7│=8

Case 2
(X - 11) = 0
X = 11

X+7 = 18
│X + 7│=18

Not Suffucient

Using 1 and 2, we get X=11 as the common siolution. Hence Answer is D (both 1 and 2 required)

by **RonPurewal** Wed Nov 05, 2008 4:41 am

this question has been posted twice in the last couple of weeks.

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