Question

The midpoint of AB is M(1, -3). If the coordinates of A are (-6, -7), what are

the coordinates of B?

Answer 1

B(8, 1)

Explanation:

M is the midpoint of AB so:

`x_B-x_M=x_M-x_A\qquad\quad\ \wedge\qquad y_B-y_M=y_M-y_A\\\\x_B-1=1-(-6)\qquad\quad\wedge\qquad\quad y_B-(-3)=-3-(-7)\\\\x_B=1+6+1\qquad\quad\ \wedge\qquad\quad y_B=-3+7-3\\\\x_B=8\qquad\qquad\ \wedge\qquad\qquad y_B=1`