Statement 1 is insufficient.
Square both the sides, you'll get 36x^2 = 3x
36x^2 - 3x = 0
Solving the above equation you will get x = 1/12 or x = 0
Therefore x has two values. from statement 2 you know x > 0. i.e. x = 1/12
Quadratic Equations
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Source: Beat The GMAT — Data Sufficiency |
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mehravikas
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hariharakarthi
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Please explain why A is not correct answer.
Using the staement 1. I got 36X^2=3x
Is there any rule on equations to not to divide or multiply by variables? Can anyone confirm this? But, I know we can not divide or multiply by a variable in inequality equation as long as we do not know the sign of the variable.
regards,
hhk
Using the staement 1. I got 36X^2=3x
Is there any rule on equations to not to divide or multiply by variables? Can anyone confirm this? But, I know we can not divide or multiply by a variable in inequality equation as long as we do not know the sign of the variable.
regards,
hhk
The poster above you answered the question. solving for x could give you x = 1/12 or x = 0. They are asking you for the value of X, so you need 1 specific number. Statement 2 eliminates the possibility that x = 0 and leaves you with x = 1/12.
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mehravikas
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You should not divide or muliply the equations like this; x^2 = x
you should always solve it in the following way:
x^2 - x = 0
x(x-1) = 0
x = 0 or 1
you should always solve it in the following way:
x^2 - x = 0
x(x-1) = 0
x = 0 or 1
hariharakarthi wrote:Please explain why A is not correct answer.
Using the staement 1. I got 36X^2=3x
Is there any rule on equations to not to divide or multiply by variables? Can anyone confirm this? But, I know we can not divide or multiply by a variable in inequality equation as long as we do not know the sign of the variable.
regards,
hhk
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heshamelaziry
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Guys, when do I check for erroneous solutions after squaring? do i check whnever i square both sides or only in certain situations ?
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mehravikas
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Can you give an equation or an example, I'll try to explain from that?
heshamelaziry wrote:Guys, when do I check for erroneous solutions after squaring? do i check whnever i square both sides or only in certain situations ?
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heshamelaziry
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mehravikas wrote:Can you give an equation or an example, I'll try to explain from that?
heshamelaziry wrote:Guys, when do I check for erroneous solutions after squaring? do i check whnever i square both sides or only in certain situations ?
y= sqrt 3y + 4
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mehravikas
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I think for such equations you have to check for erroneous solution as you will square both the sides to get a value of y.
Hope that helps..
Hope that helps..
heshamelaziry wrote:mehravikas wrote:Can you give an equation or an example, I'll try to explain from that?
heshamelaziry wrote:Guys, when do I check for erroneous solutions after squaring? do i check whnever i square both sides or only in certain situations ?
y= sqrt 3y + 4
