Question

Given point B(-1,-5) is the midpoint of points A and C(4, -1). Find the coordinates of A.

Thank you for everyone help me:)

Answer 1

mid point formula is :

`(((x_(1)+x_(2) )/(2) ),((y_(1)+y_(2) )/(2) ))\\`

and B (-1,-5) is the mid point of AC.

Assuming that x2 and y2 are coordinates of C, so x2 = 4 and y2 = -1

`(x_(1)+x_(2) )/(2) = -1\\(x_(1)+4)/(2) = -1\\ x_(1) + 4 = -2\\ x_(1) = -6`

and again,

`(y_(1)+y_(2) )/(2) = -5\\y_(1) + (-1) = -10\\{y_(1) -1 = -10\\\\{y_(1) = -9`

coordinates of A (-6,-9)