Question

Point C is the midpoint of a segment AB . What are the coordinates of point B, if: A(–1, 3), C( 1, –1)

Answer 1

Answer:

(3,-5)

Step-by-step explanation:

To find the x coordinate of the  midpoint, add the  x coordinates together and divide by 2

The x coordinate is

(x1+x2)/2

We know one point and the midpoint

( -1+x)/2 = 1

Multiply by 2

-1 +x = 2

Add 1

x =2+1

x=3

To find the y coordinate of the midpoint, add the  y coordinates together and divide by 2

The y coordinate is

(y1+y2)/2

We know one point and the midpoint

(3+y)/2 = -1

Multiply by 2

3+y = -2

Subtract 3

y = -2-3

y =-5

The other endpoint is (3,-5)

Answer 2

Answer:

B(3, -5)

Step-by-step explantion

We know that these formulas can be used to find the mid point between 2 points on a graph

$\frac{a_{1} +b_{1}}{2}= c_{1}\\ \frac{a_{2} +b_{2}}{2} =c_{2}$

Now we plot these points in

A(-1, 3), C(1, -1)

$\frac{-1+b_{1}}{2} =1 \\\frac{3+b_{2}}{2} =1$

And we can find that

$b_{1}= 3\\b_{2}=-5$

Therefore we get the answer of (3, -5)

Hope that helped you with your problem!! :)