Answer:
see explanation
Step-by-step explanation:
12
The explicit formula for a geometric sequence is
[tex]a_{n}[/tex] = a₁ [tex](r)^{n-1}[/tex]
where a₁ is the first term and r the common ratio
Here a₁ = - 1 and r = [tex]\frac{a_{2} }{a_{1} }[/tex] = [tex]\frac{-5}{-1}[/tex] = 5 , then
[tex]a_{n}[/tex] = - [tex]5^{n-1}[/tex]
13
Using the explicit formula for a geometric sequence
[tex]a_{n}[/tex] = a₁ [tex](r)^{n-1}[/tex]
where a₁ is the first term and r the common ratio
Here a₁ = - 48 and r = [tex]\frac{a_{2} }{a_{1} }[/tex] = [tex]\frac{96}{-48}[/tex] = - 2 , then
a₁₀ = - 48 × [tex](-2)^{9}[/tex] = - 48 × - 512 = 24576
