Exercise 35 Page 74

We can use the Midpoint Formula to find the missing endpoint by splitting the usual formula into two separate equations — one for the

x -

coordinate and one for the

y -

coordinate.

M (x, y) = (\frac{x _{1} + x _{2}}{2}, \frac{y _{1} + y _{2}}{2}) ⇕ x_{M} = \frac{x _{1} + x _{2}}{2} and y_{M} = \frac{y _{1} + y _{2}}{2}

To find

x_{2},

we can use the

x -

coordinate of the midpoint,

x_{M} = - 1,

and the given endpoint,

x_{1} = - 8 .