If the point (-1,2) is the midpoint of the line segment with end points that are (a,-4) and (-7,b) then what are the respective values of a and b?

Question

find values of a and b 

Answer 1

x-coordinate = (a+(-7))/2 = -1    a-7 = -2   a = 5

 

y-coordinate = (b+(-4))/2 = 2     b-4 = 4    b =8

Answer 2

The midpoint of a line segment is defined as the coordinate pair:

 

{(x₁ + x₂) , (y₁ + y₂)}

      2               2

 

If we let (x₁, y₁) = (a, -4) and (x_2, y₂) = (-7, b), then we have:

 

(a - 7)/2 = -1

 

a - 7 = -2

 

a = 5

 

and we also have

 

(b - 4)/2 = 2

 

b - 4 = 4

 

b = 8

 

Answer 3

-1 = (a - 7) / 2

2 = (-4 + b) / 2

 

Can you solve for a and b?