Question

The midpoint of AB is M(-1, –4). If the coordinates of A are (-3, -7), what are
the coordinates of B?

Answer 1

Answer:

           B(1, -1)

Step-by-step explanation:

If M(-1, 4) is midpoint of AB then:

$x_M-x_A=x_B - x_M\qquad\quad\ \wedge\qquad y_M-y_A=y_B - y_M\\\\ -1-(-3)=x_B-(-1)\qquad\wedge\qquad -4-(-7)=y_B -(-4)\\\\ -1+3=x_B+1\qquad\qquad\wedge\qquad\ \ -4+7=y_B+4 \\\\ {}\qquad x_B=1\qquad\qquad\wedge\qquad\qquad \ y_B=-1$