Question

The points A(1,3) and C(5,1) are opposite vertices of a rectangle the equation of line passing through other two vertices is y=2x+c .Then find c and other two vertices

Answer 1

The mid point of AC will also be the midpoint of BD assuming the rectangle is ABCD. So the given equation passes
through the midpoint of AC or BD.

Midpoint of AC=(5+1/2,3+1/2)=(3,2)

Now substitute the above x and y values in the given equation

2=6+c => c= -4