1 math question plz help quick

make an input - output table for the function use 0,1,2,3 as the domain


Y=21-2x

input output
0 0
1 19
2 17
3 15

come on... do you just not pay attention in class?
x is your domain and = 0, 1, 2, 3
y is your range, or the values you get when you plug your differente values for x in

so

when x=0:

21 - 2(0) = y
21 - 0 = y
y = 21

when x=1

21 - 2(1) = y
21 - 2 = y
y = 19

and so on!