OG 121 How to do it fast?

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OG 121 How to do it fast?

by fangtray » Thu Mar 22, 2012 3:29 pm
In a xy-plane, region R consists of all the points (x,y) such that 2x + 3y = 6. Is the point (r,s) in region R?

1. 3r + 2s = 6
2. R < 3 and s < 2

At first i made it into an y=mx+b equation because thats the form of the equation that i am more comfortable with working with, but then it got too confusing. Other than trying and plugging in values to find the right answer, is there an easier approach to get this under a minute? Took me 3 to get the answer.

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by [email protected] » Thu Mar 22, 2012 4:48 pm
fangtray wrote:In a xy-plane, region R consists of all the points (x,y) such that 2x + 3y = 6. Is the point (r,s) in region R?

1. 3r + 2s = 6
2. R < 3 and s < 2

At first i made it into an y=mx+b equation because thats the form of the equation that i am more comfortable with working with, but then it got too confusing. Other than trying and plugging in values to find the right answer, is there an easier approach to get this under a minute? Took me 3 to get the answer.
Are you sure the question is correct?I think we should never use the word "region" to describe a line.
It would make more sense if the equation is described as 2x + 3y >=6 or 2x + 3y <=6.
IMO E is the answer and I would post my understanding once you confirm the above point.

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by Anurag@Gurome » Thu Mar 22, 2012 7:53 pm
fangtray wrote:In a xy-plane, region R consists of all the points (x,y) such that 2x + 3y = 6. Is the point (r,s) in region R?

1. 3r + 2s = 6
2. R < 3 and s < 2

At first i made it into an y=mx+b equation because thats the form of the equation that i am more comfortable with working with, but then it got too confusing. Other than trying and plugging in values to find the right answer, is there an easier approach to get this under a minute? Took me 3 to get the answer.
See this link: https://www.beatthegmat.com/xy-plane-t87947.html
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