Question

M (3,4) is the midpoint of line JK where J has coordinates(1,2). how do i find the coordinates of K.

Answer 1

Midpoint refers to the half way point between two points, in your case between point J and K.
If J = (1,2) then K = ( x,y)
we can work out the mid point formula between them this way
Midpoint M = ( [1+x]/2 , [2+y]/2 ) = (3,4)
so we have 2 equations
a) [1+x]/2 =3
b) [2+y]/2 =4
Solve for x and y we get
x=5
y=6

So K = (5,6)