The formula to find the mid-point of a line segment give the two end points is:
#(x_M, y_M) = ((color(red)(x_1) + color(blue)(x_2))/2 , (color(red)(y_1) + color(blue)(y_2))/2)#
Where #(x_M, y_M)# is the midpoint and the given points are:
#(color(red)(x_1), color(red)(y_1))# and #(color(blue)(x_2), color(blue)(y_2))#
First, find the #x# value of the missing coordinate:
Substituting the information from the problem gives:
#4 = (color(red)(6) + color(blue)(x_2))/2#
We can now solve for #color(blue)(x_2)#:
#color(green)(2) xx 4 = color(green)(2)((color(red)(6) + color(blue)(x_2))/2)#
#8 = cancel(color(green)(2))((color(red)(6) + color(blue)(x_2))/color(green)(cancel(color(black)(2))))#
#8 = color(red)(6) + color(blue)(x_2)#
#-color(green)(6) + 8 = -color(green)(6) + color(red)(6) + color(blue)(x_2)#
#2 = 0 + color(blue)(x_2)#
#2 = color(blue)(x_2)#
#color(blue)(x_2) = 2#
First, find the #y# value of the missing coordinate:
Substituting the information from the problem gives:
#2 = (color(red)(5) + color(blue)(y_2))/2#
We can now solve for #color(blue)(y_2)#:
#color(green)(2) xx 2 = color(green)(2)((color(red)(5) + color(blue)(y_2))/2)#
#4 = cancel(color(green)(2))((color(red)(5) + color(blue)(y_2))/color(green)(cancel(color(black)(2))))#
#4 = color(red)(5) + color(blue)(y_2)#
#-color(green)(5) + 4 = -color(green)(5) + color(red)(5) + color(blue)(y_2)#
#-1 = 0 + color(blue)(y_2)#
#-1 = color(blue)(y_2)#
#color(blue)(y_2) = -1#
The coordinates of the Midpoint are: #(2, -1)#
