Answer:
b = a + 4
Step-by-step explanation:
in 1) a = 4 and b = 8
b = a + 4
8 = 4 + 4
8 = 8
in 2) a = 8 and b = 12
b = a + 4
12 = 8 + 4
12 = 12
in 3) a = 12 and b = 16
b = a + 4
16 = 12 + 4
16 = 16
in 4) a = 16 and b = 20
b = a + 4
20 = 16 +4
20 = 20
therefore, b = a + 4 is the correct equation.
