Question

Which of the points lie on the the line joining (2,0) to (4,3)?

(a) (8,9)
(b) (12,13)
(c) (-4,-1)
(d) (-6,-12)
(e) (3 1/2, 2)

Answer 1

what is the equation of the line passing through the two given points?
which of those other five points are on that line?

Answer 2

equation of the line :
y-0 3-0
---- = ------
x-2 4-2
y = (3/2 )x - 3
Put the point into the equation to see if the equation exists.

Answer 3

- so i think e. is right

- check it on diagramm

Answer 4

There should be 2 points satisfying the equation

Answer 5

There are three points...

Answer 6

Oh, I know how.

Answer 7

can you find the slope of the line given those two points?

Answer 8

(y -y1) (y2-y1)
------ = -------
(x-x1) (x2-x1)

Answer 9

or find the slope, then plug in one of the points to find the y intercept

Answer 10

y= k(x-x1) + y1

Answer 11

k : slope

Answer 12

there are lots of ways to do everything... isnt it great?

Answer 13

yea

Answer 14

Actually they are the same..
(y2-y1)
k = -------
(x2-x1)
Then you just multiply (x-x1) on both sides and +y1 on both sides

Answer 15

right , vietnam?

Answer 16

Which of the points lie on the the line joining (2,0) to (4,3)?
I assume you can get the equation of the line through 2 points?
y= (3/2) x -3

Now let's try the choices:
a) (8,9) y= 12-3= 9 yes
(b) (12,13) y= 18-3= 15 no
(c) (-4,-1) y= -6-3= -9 no
(d) (-6,-12) y= -9-3= -12 yes
(e) (3 1/2, 2) y= 21/4 -12/4 = 9/4 no

so choices (a) and (d)