Probably the easiest way to do these is to convert them to slope intercept form by solving for y. When we have y=mx+b, we read off the slope m.
-5x + 2y = 10
Add 5x to both sides,
2y = 5x + 10
Divide both sides by 2,
y = (5/2) x + (10/2)
Obviously 10/2=5 but we don't care about that for this problem. We read off the slope as
Answer: 5/2, last choice
12 = 4x - 6y
Adding 6y and subtracting 12,
6y = 4x - 12
Dividing by 6,
y = (4/6) x - (12/6)
y = (2/3) x - 2
Answer: 2/3