Question

Please help me with this #9

Answer 1

$\text{First term,} ~ a = 5\\\\\text{Common ratio,}~ r = \dfrac{10}5 = 2\\\\\text{Nth term} = ar^{n-1} = 5\cdot2^{n-1}\\\\\text{4th term } = 5\cdot 2^{4-1} = 5 \cdot 2^3 = 40\\\\\text{5th term} = 5 \cdot 2^{5-1} = 5 \cdot 2^4 = 80\\\\\text{Hence the next two terms are 40 and 80.}$