Chapter 1 - Tools of Geometry - 1-7 Midpoint and Distance in the Coordinate Plane - Lesson Check - Page 53: 2

$c(7,-8)$

Find the $x_2$ coordinate. Use the midpoint formula: $M=\frac{x_1+x_2}{2}$ $5=\frac{3+x_2}{2}$ $5\times2=\frac{3+x_2}{2}\times2$ $10=3+x_2$ $10-3=3+x_2-3$ $7=x_2$ Find the $y_2$ coordinate. Use the midpoint formula: $M=\frac{y_1+y_2}{2}$ $-2=\frac{4+y_2}{2}$ $-2\times2=\frac{4+y_2}{2}\times2$ $-4=4+y_2$ $-4-4=4+y_2-4$ $-8=y_2$