need a detail explanation

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need a detail explanation

by sana.noor » Thu Sep 26, 2013 3:29 am
Line D passes through point (-2,5), and the product of its x-intercept and yintercept is positive. Which of the following points could be on line D?

a)(5,10)
b)(-3,2)
c)(-1,7)
d)(-1,2)
e)(-3,1)

OA is D

the question says that the product of x-intercept and y-intercept is positive. it means when we multiply the values of two x=-b/m and y=b we will get -b^2/m= positive. in order to make it positive, the slope of the line must be negative to cancel the negative effect. as only option d has negative slope so it is right. but when i try drawing the figure i just messed up every thing..:(
Last edited by sana.noor on Thu Sep 26, 2013 3:35 am, edited 1 time in total.
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by GMATGuruNY » Thu Sep 26, 2013 3:33 am
Line D passes through point (-2,5), and the product of its x-intercept and yintercept is positive. Which of the following points could be on line D?

a) (5,10)
b) (-3,2)
c) (-1,7)
d) (-1,2)
e) (-3,1)
DRAW the figure:
Image

For the product of its intercepts to be positive, Line D must look like one of the two options in the figure above.
Of the five answer choices, only (-1,2) could be on line D.

The correct answer is D.
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