Question

Which of the following points lie in the solution set to the following system of inequalities?

y < -3x + 3
y < x + 2

(1, -5)

(1, 5)

(5, 1)

(-1, 5)

Answer 1

Have you considered simply substituting the values into the given inequalities?

Answer 2

What do you mean? @tkhunny

Answer 3

You are given these:

y < -3x + 3
y < x + 2

You are given a point. Let's use (1, 5)

Substitute
y < -3x + 3
5 < -3(1) + 3
5 < -6 + 3
5 < -3
This is FALSE, so (1,5) is no good. Move on to the next one.
Since it doesn't work in the first one, there is no need to check the second.