Hi,
Help much appreciated
Cheers
X-Y co ordinate problem GMAT prep
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We know the slope, and we know points that exist on the line. That's all we need to know. So both are independently sufficient.
If you have a tough time seeing this:
from the question we know that y=(3/4)x +b
Now throw in the coordinates we get from (1) and (2):
for (1):
4 = (3/4)*4 + b
4 = 3 + b
so b = 1
therefore the equation is y = (3/4)x +1
for (2):
-2 = (3/4) *-4 + b
-2 = -3 + b
b = 1
therefore the equation is y = (3/4)x +1
Since both equations are the same we can eliminate answers A,B and C, since we know that each one will either be independently sufficient or neither can be sufficient.
Now we can see if the point is on the line by asking the question:
does (1/2) = (3/4)(-2/3) + 1?
(1/2) = -(1/2) + 1
(1/2) = (1/2)
So yes, the point is on the line.
If you have a tough time seeing this:
from the question we know that y=(3/4)x +b
Now throw in the coordinates we get from (1) and (2):
for (1):
4 = (3/4)*4 + b
4 = 3 + b
so b = 1
therefore the equation is y = (3/4)x +1
for (2):
-2 = (3/4) *-4 + b
-2 = -3 + b
b = 1
therefore the equation is y = (3/4)x +1
Since both equations are the same we can eliminate answers A,B and C, since we know that each one will either be independently sufficient or neither can be sufficient.
Now we can see if the point is on the line by asking the question:
does (1/2) = (3/4)(-2/3) + 1?
(1/2) = -(1/2) + 1
(1/2) = (1/2)
So yes, the point is on the line.