Lesson: Graphing Lines

Comment on Graphing Lines

Pls help with the following question: https://gmatclub.com/forum/on-the-graph-above-when-x-1-2-y-2-and-when-x-1-y-136560.html (Question No. 8 from OG 2017)
gmat-admin's picture

Is this why we say that a straight line is made of an infinite number of dots?
gmat-admin's picture

You bet! The same applies to the number line.

Cheers,
Brent

Hi Brent,
Grateful if you could provide me with your approach to solve this problem.
Thanks

In the xy-coordinate system, if (a, b) and (a+3, b+k) are two points on the line defined by the equation x = 3y - 7, then k =

A) 9
B) 3
C) 7/3
D) 1
E) 1/3

Please provide explanation!!
gmat-admin's picture

Glad to help!
Here's my full solution: https://gmatclub.com/forum/in-the-xy-coordinate-system-if-a-b-and-a-3-b-...

Cheers,
Brent

Hi Brent,
Just checking for this question: I found it easier and faster to answer using this approach, is it sound?

Question:
In the xy-coordinate system, if (a, b) and (a+3, b+k) are two points on the line defined by the equation x = 3y - 7, then k =
_________
Answer:
All i did was find the x intercept and substituted to get the why intercept.

So...
x= 3(0) -7
x=-7

(-7+3, 0+k)

-4=3y-7
y=1

(a+3,b+k)
(-7+3, 0+1)

therefore k=1

I think its a right approach that i hope to use in future, will it work or did I just get lucky?

Thanks in advance for your help,
Kamo
gmat-admin's picture

Great work, Kamo!
That's a well-reasoned solution

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