The lines with equations:
y = x + 1,
y = mx − 1,
& y = −4x + 2m
pass through the same point.
Determine all possible values for m.
y = x+1
y = mx  1
x+1 = mx  1
(m1)x = 2
x = 2/(m1)
y = 2/(m1) + 1
2/(m1) + 1 = 8/(m1) + 2m
2 + m  1 = 8 + 2m(m1)
2m^2  2m  8  2  m + 1 = 0
2m^2  3m  9 = 0
m = (3 +/ sqrt(9 + 72)) / 4
m = (3 +/ sqrt(81)) / 4
m = (3 +/ 9) / 4
m = 3 or 1.5

Posted by Charlie
on 20180107 12:24:25 