In the xyplane, does the line with equation y = 3x+2 contain the point (r,s)?
(1) (3r+2s)(4r+9s)=0
(2) (4r6s)(3r+2s)=0
I got D, but the right answer is C. Can anyone please explain? Thanks!
GMAT Prep 1 DS 19
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In the xyplane, does the line with equation y = 3x+2 contain the point (r,s)?
(1) (3r+2s)(4r+9s)=0
i.e 3r+ 2 s =0 or 4r+9s =0
s =3r+2 or s =4r +9
INSUFF r,s an lie on either of the lines
(2) (4r6s)(3r+2s)=0
4r6s =0 i.e s =4r6
or
3r+2s =0 i.e 3r+2 =s
INSUFF same as above
Combine s =3r+2 or s =4r +9 & s =4r6 or 3r+2 =s
now since both the stmts are true s=3r+2 which satisfies both stmts
so s =3r +2 equivalent to y = 3x+2
SUFF
C
(1) (3r+2s)(4r+9s)=0
i.e 3r+ 2 s =0 or 4r+9s =0
s =3r+2 or s =4r +9
INSUFF r,s an lie on either of the lines
(2) (4r6s)(3r+2s)=0
4r6s =0 i.e s =4r6
or
3r+2s =0 i.e 3r+2 =s
INSUFF same as above
Combine s =3r+2 or s =4r +9 & s =4r6 or 3r+2 =s
now since both the stmts are true s=3r+2 which satisfies both stmts
so s =3r +2 equivalent to y = 3x+2
SUFF
C
Regards
Samir
Samir