Answer:
see explanation
Step-by-step explanation:
To find the first 4 terms, substitute n = 1, 2, 3, 4 into the n th term formula
n = 1 : 3(1 + 3) = 3 × 4 = 12
n = 2 : 3(2 + 3) = 3 × 5 = 15
n = 3 : 3(3 + 3) = 3 × 6 = 18
n = 4 : 3(4 + 3) = 3 × 7 = 21
The first 4 terms are 12, 15, 18, 21
Substitute n = 50 into the n th term formula
n = 50 : 3(50 + 3) = 3 × 53 = 159 ← 50 th term
Equate n th term formula to 100, that is
3(n + 3) = 100
3n + 9 = 100 ( subtract 9 from both sides )
3n = 91 ( divide both sides by 3 )
n = 30.333...
Thus the first term to have a value larger than 100 is the 31 st term
