k=4/2=2
y=2x+m
y^2=6(y-m)
y^2-6y+6m
√15=√[1+(1/4)]√[(y1+y2)^2-4y1y2]
√15=(√5/2)√[36-24m]
2√3=√(36-24m)
12=36-24m
24m=24
m=1
y=2x+m