GMATprep: all points (x,y) that lie below

nhai2003 wrote:Please explain why the answer is E????

OA: y<-1/2*x+3

But if x=5, y =2, 2<-1/2*5+3 => 2<0.5 doesn't make sense!

pl check your attached file....something wrong...

real2008 wrote:

nhai2003 wrote:Please explain why the answer is E????

OA: y<-1/2*x+3

But if x=5, y =2, 2<-1/2*5+3 => 2<0.5 doesn't make sense!

pl check your attached file....something wrong...

Thanks I have attached new file

Guys Please Help Me!

sets below the line.... therefore (5,2) can't be used... try for example (-5,-1) and u'll see that only option E

shibal wrote:sets below the line.... therefore (5,2) can't be used... try for example (-5,-1) and u'll see that only option E

why set (5,2) can't be used? It said se (x,y) below the line (6,3)

draw the coordinate system and the line, and then point out 5,2.... u'll see the point is above the line....

from the graph you may find x axis intercept is (a) 6 and for Y axis (b) is 3.

If these two intercepts are known, the eqn can be written in this form

x/a + y/b = 1

Now,

x/6 + y/3 = 1

rearranging,

y= 3- x/2 (first form)

x+2y-6=0 (second form)

now as the mentioned point lies below the line , i.e. to the side where origin also lies, then the expression x+2y-6 for a point lying below the line [say (1,1)] will have same polarity as the expression for (0,0) has.

so for (0,0) the expression x+2y-6= -6
[for (1,1) the expression x+2y-6= -3]

that means x+2y-6<0
or, 2y<6-x

or, y<3-x/2

i.e choice E

HTH