GMATD11 wrote:
ln the coordinate plane, line k passes through the origin and has slope 2. lf points (3,y) and (x,4) are on line k, then x+y =
(A) 3.5
(B) 7
(C) 8
(D) 10
(E) 14
i used the method y2-y1/x1-x2 =2
4-y/x-3 =2
As line passes through origin y=2x
Upon solving both the equation i get x+y=7.5
OOps some different method required.
Guys is this the trick in Coordinate geometry that we generally have to put points in line and chk.instead of making equations with the points given.
Pls comment
@Fluke ---i searched this question but didn't found.
To find the line k, knowing a point through which it passes and the line's slope is sufficient.
Since it passes through origin and has slope 2, this is what it will look like:
Attachment:
Ques6.jpg
What is the meaning of slope? It means for every increase of 1 unit in x coordinate, y coordinate increases by 2 units. When x coordinate increases by 3 units (from the point (0,0)), y coordinate increases by 6 units. Hence the line passes through (3, 6). y must be 6.
When y coordinate increases by 4 units (from (0,0)), x coordinate must have increased by 2 units. The line must pass through (2, 4). x must be 2.
x+y = 2+6 = 8
, I found this very interesting. Is there any article specifying this theory more in detail with a few examples? would greatly help in solidifying the learning!!