Stat 1). You have 2 unknowns which you cannot solve for
(3r + 2 -s) (4r + 9 - s ) = 0
=> 3r + 2 - s = 0 : Two variables. Cannot solve for either one
=> 4r + 9 - s = 0 : Two variables. Cannot solve for either one
Stat 2) Same. You have 2 unknowns which you cannot solve for
(4r - 6 - s) (3r + 2 - s ) = 0
=> 4r - 6 - s = 0 : Two variables. Cannot solve for either one
=> 3r + 2 - s = 0 : Two variables. Cannot solve for either one
Combined
You can eliminate one of the variables ( r or s ) and find the answer to see if it contains the point.
Does r,s lie on the line
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Source: Beat The GMAT — Data Sufficiency |
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jcan-gmatter
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gmatrant
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Hmm...jcan-gmatter wrote:Stat 1). You have 2 unknowns which you cannot solve for
(3r + 2 -s) (4r + 9 - s ) = 0
=> 3r + 2 - s = 0 : Two variables. Cannot solve for either one
=> 4r + 9 - s = 0 : Two variables. Cannot solve for either one
Stat 2) Same. You have 2 unknowns which you cannot solve for
(4r - 6 - s) (3r + 2 - s ) = 0
=> 4r - 6 - s = 0 : Two variables. Cannot solve for either one
=> 3r + 2 - s = 0 : Two variables. Cannot solve for either one
Combined
You can eliminate one of the variables ( r or s ) and find the answer to see if it contains the point.
In the first case I have two equations
3r + 2 - s = 0
4r + 9 - s = 0
Can I solve for r ans s.
Similarly for case 2.
So shouldnt answer be D.
your comments.
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gabriel
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You cannot solve 3r + 2 - s = 0, 4r + 9 - s = 0 simultaneously to get a value for r and s .... Remember to solve two linear equations simultaneously the variables need to satisfy both the equation eg. 2x+3y=5 and 3x+2y=5 over here both the equations are truegmatrant wrote:Hmm...jcan-gmatter wrote:Stat 1). You have 2 unknowns which you cannot solve for
(3r + 2 -s) (4r + 9 - s ) = 0
=> 3r + 2 - s = 0 : Two variables. Cannot solve for either one
=> 4r + 9 - s = 0 : Two variables. Cannot solve for either one
Stat 2) Same. You have 2 unknowns which you cannot solve for
(4r - 6 - s) (3r + 2 - s ) = 0
=> 4r - 6 - s = 0 : Two variables. Cannot solve for either one
=> 3r + 2 - s = 0 : Two variables. Cannot solve for either one
Combined
You can eliminate one of the variables ( r or s ) and find the answer to see if it contains the point.
In the first case I have two equations
3r + 2 - s = 0
4r + 9 - s = 0
Can I solve for r ans s.
Similarly for case 2.
So shouldnt answer be D.
your comments.
Whereas in the above equation we say 3r+2-s = 0 or 4r+9-s = 0 that is both of them are not true..that is only one of them is equal to 0 ..
Regards.
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sujaysolanki
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lawalx ..i will try to be put it in a simple way and as gabriel has put it earlier ..let me know if it makes sense
Let (3r + 2 -s) = a and (4r + 9 - s ) = b (4r - 6 - s) = c
From 1
a * b = 0 so this means either a is 0 or b is 0 ..but we cant say which one
From 2
c * a = 0 so this means either a is 0 or b is 0 ..but we cant say which one
Combining a = 0 ..which gives the same equation as the stem
Hope this helps
Let (3r + 2 -s) = a and (4r + 9 - s ) = b (4r - 6 - s) = c
From 1
a * b = 0 so this means either a is 0 or b is 0 ..but we cant say which one
From 2
c * a = 0 so this means either a is 0 or b is 0 ..but we cant say which one
Combining a = 0 ..which gives the same equation as the stem
Hope this helps
