c circle the tables that show an additive pattern ($y = x + a$).

Explanation:

Step1: Check the first table

For (x = 2,y=3), if (y=x + a), then (3=2 + a), (a = 1). Check (x = 4), (y=4 + 1=5) (matches). Check (x = 6), (y=6 + 1=7) (matches). Check (x = 8), (y=8 + 1=9) (matches).

Step2: Check the second table

For (x = 1,y = 7), if (y=x + a), then (7=1+a), (a = 6). Check (x = 2), (y=2 + 6=8\neq14) (does not match).

Step3: Check the third table

For (x = 5,y = 8), if (y=x + a), then (8=5+a), (a = 3). Check (x = 10), (y=10 + 3=13) (matches). Check (x = 15), (y=15 + 3=18) (matches). Check (x = 20), (y=20 + 3=23) (matches).

Step4: Check the fourth table

For (x = 0,y = 5), if (y=x + a), then (a = 5). Check (x = 1), (y=1 + 5=6) (matches). Check (x = 2), (y=2 + 5=7) (matches). Check (x = 3), (y=3 + 5=8) (matches).

Step5: Check the fifth table

For (x = 4,y = 8), if (y=x + a), then (8=4+a), (a = 4). Check (x = 8), (y=8 + 4=12\neq16) (does not match).

Step6: Check the sixth table

For (x = 3,y = 7), if (y=x + a), then (7=3+a), (a = 4). Check (x = 6), (y=6 + 4=10) (matches). Check (x = 9), (y=9 + 4=13) (matches). Check (x = 12), (y=12 + 4=16) (matches).

Answer:

The first, third, fourth and sixth tables.