A function means that each x value has only one y value.
1. Function; Domain: -3, -1, 0, 1; Range: -5, 1, 4, 7
2. Not a function; Domain: 1, -1, -2; Range: -2, 2, 4, 3
To make an equation, you have to find the difference in y divided by the difference in x.
3. y=-8/3x+1/3
4. y=5/3x
To find the y intercept, make x into 0 and to get the x intercept, make y into 0.
5. x intercept: (7/2,0)
y intercept: (0,-1)
6. x intercept: (9/2,0)
y intercept: (0,6)