Answer
(a) The midpoint is $(4,9)$
(b) The midpoint is $(\frac{7}{2},-3)$
Work Step by Step
(a) We can find the midpoint of the line segment joining the two points $(1,3)$ and $(7,15)$:
$x = \frac{1+7}{2} = 4$
$y = \frac{3+15}{2} = 9$
The midpoint is $(4,9)$
(b) We can find the midpoint of the line segment joining the two points $(-1,6)$ and $(8,-12)$:
$x = \frac{-1+8}{2} = \frac{7}{2}$
$y = \frac{6+(-12)}{2} = -3$
The midpoint is $(\frac{7}{2},-3)$
