This would be equivalent to saying x*y = 0
therefore x = 0 and y = 0.
while it is possible for both to equal 0, only x OR y must equal 0.
This question is just a simple case of number of equations, number of unknowns. each option gives you 1 distinct equation, with 2 unknowns in it. Since no new variables are introduced in either equation, it would be possible to solve the equations simultaneously.
Answer is C
gmat740 wrote:OA is D
I. (3r + 2 - s)(4r + 9 - s) = 0
so
(3r + 2 - s) = 0
(4r + 9 - s) = 0
solve both these eqn's
s= -19
r = -7
now our equation is
y = 3x +2
so for a point to lie on the lie, it must satisfy the equation of line
s = 3r + 2
Put the values of r and s
-19 = 3(-7)+2
-19= -19
Hence (r,s) lie on the line.
II. (4r - 6 - s)(3r + 2 - s) = 0
(4r - 6 - s) = 0
(3r + 2 - s) = 0
proceed just like the steps above and you will get two different values of r and s
put those values of r and s back into the eqn of the line and check whether they satisfy or not
So both statements are suff
So answer D
Hope this Helps
Karan
