BTGmoderatorDC wrote:If (x+y)/z = -2, is x positive?
(1) z is negative.
(2) y is positive.
Source: GMAT Prep
$$x + y + 2z = 0\,\,\,,\,\,\,z \ne 0\,\,\,$$
$$x\,\,\mathop > \limits^? \,\,0$$
$$\left( {1 + 2} \right)\,\,y > 0\,\,,\,\,z < 0\,\,\,\,\,\left\{ \matrix{
\,{\rm{Take}}\,\,\left( {x,y,z} \right) = \left( {1,1, - 1} \right)\,\,\,\, \Rightarrow \,\,\,\left\langle {{\rm{YES}}} \right\rangle \,\, \hfill \cr
\,{\rm{Take}}\,\,\left( {x,y,z} \right) = \left( { - 1,3, - 1} \right)\,\,\,\, \Rightarrow \,\,\,\left\langle {{\rm{NO}}} \right\rangle \,\, \hfill \cr} \right.\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,\,\left( {\rm{E}} \right)$$
We follow the notations and rationale taught in the GMATH method.
Regards,
Fabio.
