What is the value of y?
(1) 3| x^2 - 4| = y - 2
(2) |3 - y| = 11
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value of y
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j_shreyans
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Statement 1: 3|x² - 4| = y - 2.What is the value of y?
(1) 3|x2 - 4| = y - 2
(2) |3 - y| = 11
If x=0, then y=14.
If x=2, then y=2.
Since both y=14 and y=2 are possible, insufficient.
Statement 2: |3 - y| = 11.
Solving 3-y = 11 and 3-y = -11, we get:
y = -8 or y=14.
Since both y = -8 and y=14 are possible, insufficient.
Statements 1 and 2 combined:
Statement 2 requires that y = -8 or y=14.
Plugging y = -8 into 3|x² - 4| = y - 2, we get:
3|x² - 4| = -8-2
3|x² - 4| = -10
Not possible, since the left side cannot yield a negative result.
Thus, y=14.
Sufficient.
The correct answer is C.
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j_shreyans
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Hi ,
Whats wrong with the below method.
Statement 1: 3|x^2-4|=y-2
if i solve this
3x^2-12=y-2
3x^2-y=10 ..............(1)
3|x^2-4|=y-2
so 3x^2-12=-y+2
3x^2+y=14 .............(2)
from 1 and 2
x=2 & -2
if we put x in 3|x^2-4|=y-2
so we will get y = 2
Please advise and correct me.
Thanks,
Whats wrong with the below method.
Statement 1: 3|x^2-4|=y-2
if i solve this
3x^2-12=y-2
3x^2-y=10 ..............(1)
3|x^2-4|=y-2
so 3x^2-12=-y+2
3x^2+y=14 .............(2)
from 1 and 2
x=2 & -2
if we put x in 3|x^2-4|=y-2
so we will get y = 2
Please advise and correct me.
Thanks,
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Hi j_shreyans,
The equation that we're given in Fact 1 has an INFINITE number of solutions, so part of the problem is that you're focusing on just X=2 and X=-2.
As it stands, BOTH of those values of X lead to Y equaling 2, which does NOT fit the equation given in Fact 2. This is a wordy way of saying that you're discussing numbers that are NOT solutions to the system of equations that we're given.
GMAT assassins aren't born, they're made,
Rich
The equation that we're given in Fact 1 has an INFINITE number of solutions, so part of the problem is that you're focusing on just X=2 and X=-2.
As it stands, BOTH of those values of X lead to Y equaling 2, which does NOT fit the equation given in Fact 2. This is a wordy way of saying that you're discussing numbers that are NOT solutions to the system of equations that we're given.
GMAT assassins aren't born, they're made,
Rich
