Question

M is the midpoint if AB . If coordinates of A are (-1,5) and the coordinates of M are (3,3) , what are the coordinates of B?

Answer 1

The co-ordinates of B are ( 7,1)

Explanation:

Step(i):-

Given that 'M' is the midpoint of AB

Given co-ordinate points are A(-1,5) and midpoint M(3,3)

we know that the midpoint formula

`midpoint = ((x_(1) +x_(2) )/(2) ,(y_(1)+y_(2) )/(2) )`

`(3,3) = ((-1+x_(2) )/(2) ,(5+y_(2) )/(2) )`

Step(ii):-

Equating

`3 = (-1+x_(2) )/(2)` and
`(5+y_(2) )/(2) = 3`

cross multiplication, we get

6 = -1 + x₂ and 6 = 5 +y₂

x₂ = 6+1 and y₂ = 6-5

x₂ = 7 and y₂ = 1

Final answer:-

The co-ordinates of B are ( 7,1)