# How do you find the missing coordinate if the 1st coordinate is (3,0) and the midpoint is (0,5)?

Jul 7, 2016

The other endpoint is at (-3,10)

#### Explanation:

The midpoint is in the middle of the line and is found from averaging the x-values and averaging the y values.
Let's call the missing coordinates of the other endpoint of the line (x_1, y_1)

Write equation to show how the midpoint was calculated in the first place.

$\frac{3 + {x}_{1}}{2} = 0 \text{ and } \frac{0 + {y}_{1}}{2} = 5$

$3 + {x}_{1} = 0 \text{ } 0 + {y}_{1} = 10$

${x}_{1} = - 3 \text{ } {y}_{1} = 10$

The other endpoint is at (-3,10)