Explanation:
Well there is no real answer to this, but, replace the numbers, -1, 0 and 1 with the x, for example,
If x is -1, then y is
y=2*-1 + 1 which is -1, so y is -1
y=-1
second, for 0, 2*0+1 is 1, so y is 1
y=1
Third, if x is 1 then y is, y=2*1+1 so y is 3
y=3
so you're 3 y's would be, -1, 1 and 3.
Cheers!