Question

i posted this question so many times..
plseeeeeeee can any one solve this

Answer 1

have you tried drawing it out on a coordinate system first

then applying the distance forumla

Answer 2

can u plse help me or guide
so that i can solve it myself

Answer 3

move it to the origin .... itll make life that much simpler

Answer 4

subtract A from all the points

A(-1,2), B(2,1) c(3,4) D(1,2)
1 -2 1 -2 1 -2 1 -2
---------------------------
0,0 3,-1 4,2 2,0

Answer 5

find out where the line AC crosses BD from these points

Answer 6

im not sure what the external ratio stuff means tho,

id even move the crossing point to the origin afterwards ... that way you can compare lengths and such

Answer 7

Here is a graph of your problem
your problem is to show
\[ \frac{|BE|}{|DE|}= \frac{5}{2} \]
where |BE| means the length of the line segment BE

one way to solve is to find the equation of the line between A and C
and the equation between points B and D
then find where those two equations intersect (at point E)

finally, find the distance between the points B and E and the distance between D and E
show the ratio of the whole to the external is 5/2

Answer 8

okay
but how to find the equation of the line between A and C

Answer 9

this shows how
http://www.mathsisfun.com/algebra/line-equation-2points.html

the first step is find the slope "m" between the two points

then use
y- y1 = m(x-x1) where (x1,y1) is one of the points (either will work)
then simplify

Answer 10

okay, let me solve

Answer 11

A(-1,2), c(3,4)
slope= 2/4=1/2
B(2,1),D(1,2)
slope=1/-1=-1

Answer 12

what after next

Answer 13

for the equation of the line through pts A and C
use y - y1 = m( x - x1) where you can use m= 1/2, and (x1,y1) is pt A (-1,2)
you get
y- 2 = (1/2)*(x - -1)
y -2 = (1/2)x + 1/2
y= (1/2) x + 5/2

use the same equation to find the equation of the line through pts B and D
except m= -1 and use point B or D for (x1,y1)

once you have the two equations, you can set their y values equal to find where they intersect. once you solve for x, you can find y and you have point E

then use the distance formula (google it if you don't remember it)

Answer 14

for the equation of the line through pts B and D
y- 1 = (-1)*(x -2)
y -1 = -x+2
y= -x+2+1
y=-x+3

Answer 15

@phi

Answer 16

from y= (1/2) x + 5/2 and y=-x+3
we get,
(1/2)x+5/2=-x+3
(1/2)x+x=3-(5/2)
(3/2)x=1/2
x=1/3

Answer 17

@phi plse see if it is right

Answer 18

is there a typo between pts A,B.C, or D ?

Answer 19

**x= 1/3 is good
now find y using either y= (1/2) x + 5/2 or y=-x+3
you will get the same y, because this is the point where the lines cross

once you have the location of point E (1/3, ?)
you can find the distance between point B and E
and the distance between point D and E
the ratio of those distances should be 5/2

See http://www.purplemath.com/modules/distform.htm
for the distance formula