Question

If M (-2, 5) is the midpoint of

CD and the coordinates of C are (4, 7), what are the coordinates of D?

Answer 1

soln ,given,

midpoint of CD=M(-2,5)

let,

C(4,7)=(x1,y1)

D(x1,y2)=?

now by using midpoint formula =(x1+x2)/2+(y1+y2)/2

M(-2,5)=( 4+x2)/2+(7+y2)/2

comparing both sides

-2=(4+x2)/2

-4=4+x2

-4-4=x2

threfore,x2= -8

again

5=(7+y2)/2

10=7+y2

therefore,y2=3

thus , the coordinate of D is D(-8,3)