Question

First question. The midpoint of SR is...

Answer 1

The formula of a midpoint SR:

$M\left(\dfrac{x_S+x_R}{2},\ \dfrac{y_S+y_R}{2}\right)$

We have

S(4, 1) and M(7, -5)

Substitute:

$\dfrac{4+x_R}{2}=7\qquad|\cdot2\\\\4+x_R=14\qquad|-4\\\\x_R=10\\\\\dfrac{1+y_R}{2}=-5\qquad|\cdot2\\\\1+y_R=-10\qquad|-1\\\\y_R=-11$

Answer: R(10, -11)