Question

The midpoint of segment QR is M(-2, 9). One end point of segment QR is Q(-8, 12). Find the coordinates of the other endpoint, R.

Answer 1

Here,

The midpoint of segment QR is M

m(-2,9) x3=-2,y3=9

Q=(-8,12)x1=-8,y1=12

R=x2,y2

we know that,

`\tt{ m=(Q+R)/(2) }` ⠀

So,

x3=
`\tt{(x1+x2)/(2) }` ⠀

`\tt{-2=(-8+x2)/(2) }` ⠀

`\tt{-2×2=-8+x2 }` ⠀

`\tt{x2=8-4 }` ⠀

`\tt{x2=4 }` ⠀

x2=4

now we find the y coordinate y2.

y3=
`\tt{(y1+y2)/(2) }` ⠀

`\tt{9=(12+y2)/(2) }` ⠀

`\tt{9×2=12+y2 }` ⠀

`\tt{y2=18-12 }` ⠀

`\tt{y2=6 }` ⠀

y2=6

Now we get the two coordinate of R

so,

R=(x2,y2)=(4,6)