Hi,
Note that P is to the upper side of lines m and n. And P is to the lower side of line L.
So we can shift the focus to line L's equation as it is different from the other 2.
The answer should be something involving y = 3x - 3. And D: 3r - t < 3 gets that. So pick D.
If you want to go further:
P is to the lower side of line L means y(P) < 3*x(P) - 3
To come up with the above conclusion, take H (r,z) on the line L. H has the same x coordinate with P and is above P,then z>t. Meanwhile, z = 3r - 3 ( z belongs to line L), so t < 3r - 3,
or we can say t - 3r <3 ,and this is different from 3r - t < 3 in D.
Hope it helps.
"There is nothing either good or bad - but thinking makes it so" - Shakespeare.
