math question is this the right answer?

Question

line segment CD the mid point is (2, -5/2) and the end point is C (-2,-1)

are the coordinates of the other endpoint D(6,4)

i used the mid point formula it did this

-2-x
--------=2
2

i mulitplied by 2 and got
-2-x=4
-x=6
x=-6


and then i did

-1-y
-------= -5/2
2

i muliplied by 2 and got

-1-y=-5
-y=-4
y=4
2

and if that is right then what is the distance between the 2

Answer 1

I think you're mixing up the slope formula and the midpoint formula.

In the midpoint formula, you need to add on top. (It's the slope formula where we subtract.)

So, change it to
-2+x
--------=2
2

Then you'll get +6=x

Same idea for y, switch so that you add:
-1+y
-------= -5/2
2

And y=-4

I can't do subscripts, so x1 means x subscript 1, etc.

Distance formula = sqrt ((x2-x1)^2+(y2-y1)^2)
sqrt((6--2)^2+(-4--1)^2
sqrt(8^2+(-3)^2)
sqrt 73=8.54

Answer 2

Wait. Your work shows the other endpoint is (-6,4) but your question is asking whether the other endpoint is (6,4). First of all, check your question.

Second of all, both answers are not correct. For a line segment, you should think of the midpoint as the average of the two endpoints. In that case, what you want to solve for is :

(-2+X)/2 = 2 and (-1+Y)/2=-5/2

The distance between two points is given by the following equation below. Once you have the two correct endpoints, you can just plug it into the equation to find the distance.

D=sqrt[(X1-X2)^2+(Y1-Y2)^2]

Answer 3

I think you're sort of on the right track. To help you answer this question yourself I want you to take out a piece of graph paper and make a graph with .5 as each increment. (i.e., from 0 your first point to the right would be .5, then 1, then 1.5, then 2.0, then 2.5 etc), then I want you to mark those coordinates on the graph. Mark one C and put it's quard's in ( ....,....) and then mark the midpoint with it's coord..s (2, -2.5). Now draw a line from one to the other. Now assuming all lines travel from left to right and since the midpoint would be to the right of C then your end point would be past the midpoint so keep drawing your line until it looks like twice the distance. Now count how many squares to the right you have to move from point C to get to the vertical line of the midpoint. Then count how many squares down you have to go to get to the horizontal line of your midpoint. Write them down as (x,y). This is your distance from point C to your midpoint. The formula you should use is the distance formula. So now take that number and add it to the coordinates for the midpoint (2.-2.5)
+ (x, y )
________
__(....,....) (THESE ARE THE ENDPOINT'S COORD.S)

The formula you are trying to use is the formula to find the measurement of half the distance between points. But remember that is just the measurement of the distance, in order to get the COORDINATES of the midpoint you must add the distance to the midpoint to the first set of coordinates. For example if the half the distance between 2 and 4 = 1, then the midpoint between 2 and 4 would be 2+1=3. You see?

Answer 4

the other endpoint should be: (6,-4)
distance between the two endpoints:
sq.rt.{(-2-6)^2 + (-1-[-4])^2}
sq.rt.[(-8)^2 + 3^2]
sq.rt.(64+9)
sq.rt. 73