+0  
 
0
128
1
avatar

let X, Y, and Z be points such that XZ/XY = ZY/XY = 1/2 . if Y= (1, 7) , Z= (-1, -7), then what is the sum of the coordinates of X?

 Apr 26, 2019
 #1
avatar+106539 
+2

If  XZ/XY  = ZY/XY  = 1/2

 

Then   XZ = ZY

 

Then Z must be the midpoint of  XY

 

So

 

[ 1 + x coord of X ] / 2  =  -1    multiply through by 2

 

1 + x coord of X  =  -2      subtract 1 from both sides

 

x coord of X = - 3

 

And 

 

[ 7 + y coord of X ] / 2  = -7

 

7 + y coord of Y  =  -14      subtract 7 from both sides

 

y coord of Y = -21

 

So X  = (-3, -21)   and the sum of the coordinates  =  -24

 

 

cool cool cool

 Apr 26, 2019

31 Online Users