Answer:
33480783
Step-by-step explanation:
Finding the Common Ratio:
We know that the formula for the common ratio of a GP is:
r = aₙ / (aₙ₋₁) (Where n is any integer)
replacing the values, taking n=2
r = -21 / 7
r = -3
Solving for the 15th Term:
We know that the Formula for the nth term of a GP:
G(n) = a * r ⁿ⁻¹ (where a is the first term and r is the common ratio)
replacing the values (taking n = 15 since we need the 15th term)
G(15) = 7 * (-3)¹⁴
G(15) = 33480783
Hence, the 15th term of the given GP is 33480783
