Question

What is the 7th term of the geometric sequence 4, -20, 100

Answer 1

1st let's calculate r the common ratio:
 r = (-20)/4 = (100/-20) = -5

Value of nth term = a₁.rⁿ⁻¹, where a₁= 1st term and n, the rank

Value of nth term = 4r⁽⁷⁻¹⁾ = 4.(-5)⁶

Value of nth term = 62,500