An = a1 * r^(n-1)
n = term to find = 18
a1 = first term = 3
r = common ratio = 4/3
now we sub
a18 = 3 * 4/3^(18 - 1)
a18 = 3 * 4/3^17
a18 = 3 * 133
a18 = 399
Answer:
A u B = {3,5,6,7,8,11,12}
Step-by-step explanation:
A = {3,6,7,11}
B = {3,5,7,8,12}
A u B = {3,5,6,7,8,11,12}
