Coordinate Geometry gmatprep

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Source: — Data Sufficiency |

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by pepeprepa » Sat Aug 09, 2008 6:45 am
See the graphs I did with examples and counter examples for 1) 2) and 1&2)

1)
Intercept or not the circle.

2)
Intercept or not the circle.

1)and2)
Intercept or not the circle.

Try to draw a graph to see answer B is not possible.
Tell me if it's ok.
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by [email protected] » Sat Aug 09, 2008 8:25 am
Hi Thanks very much for your post I am still not sure I understand how you can tell what a line would look like from the slope -1/10.

Thanks
Karen

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by pepeprepa » Sat Aug 09, 2008 9:27 am
y=-1/10x + b
It means you can draw an infinity of lines which are parallel, the difference is their b. b is the value of y when x=0
So you can draw many lines with a slope of -1/10 with b=-1 b=1 b=0 .......

-1/10 means the line goes down from left to right and for each 10 horizontal movement (x), the line goes down of 1 on the vertical (y).

Check your math review.