The slope of (-2, 3) & (1, 1) is ( 4, 2). The reason why the answer is (4, 2) is that if you look at a number line from left to right you'd see that -2 takes four steps to get to positive 2.
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10
↑ ↑ ↑ ↑ ↑
1 2 3 4
As for the other plot, you have to think: How many times does 1 need to jump to get to 3?
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10
↑ ↑ ↑
1 2
This is important to remember, the numbers to your right is your y and the numbers to your left is your x.
(-2, 3) (1, 1)
↑ ↑
y y
(-2, 3) (1, 1)
↑ ↑
x x
I hope I helped :)