Heidi is wrong.
If you substitute the x in y= x + 3 with the x values given at the table, you get different answers than the ones given on the table for the most part.
-2 + 3 equals 1 not -7
-1 + 3 equals 2 not -4
0 + 3 equals 3 not -1
1 + 3 equals 4 not 2
2 + 3 equals 5. This is the y value in the table. But for y= x + 3 to be the rule, the y value in the table and the y value we get from substituting the x value into y= x + 3 would have to be correct every time