#1**0 **

Same thing as last time. Pull out 15 from both - a1 = 1, a3 = 9.

Ask: What can I multiply 1 by twice to get 9?

\(1 * x * x = 9\)

\(9 = x^2, x = 3\)

Okay so if a geometric equation is of form:

\(y=ab^x\)

Then a = 15 (what we pulled out to make the problem easier to solve) and b = 3

\(y = 15(3^x)\)

Guest May 7, 2021

#2**+1 **

a1 * r * r = a3

15 r^2 = 135

r^2 = 9

r = 3

an = a1 (3^{n-1})

an = 15 * 3^{n-1}

ElectricPavlov May 7, 2021