USE ARITHMETIC OR GEOMETRIC SEQUENCE TO SOLVE. Lisa wants to get a new phone. An iPhone 12 is $800 while an iPhone 8 is $600. If the iPhone 12's price goes down by 10% each year and the iPhone 6's goes down by 5% each year, Which phone would be the cheapest for Lisa to get after three years?

iPhone 12

The iphone 8

Step-by-step explanation:

To find the nth term of a geometric sequence we have the following equation

ar^(n-1)

where a is the first term

r the is the common ratio

n is the term

we can see that the first term for the iphone 12 is 800, the common ratio is .9 (1-.1), and we need the third term

Therefore the price of an iphone 12 after 3 years is

800*.9^(3-1)

which is 648

The iphone 8's first ter is 600 and the common ratio is .95 (1-.05)

using the same equation

600*.95^(3-1)

which is 541.5

i found two solutions,   n = 2 • ± √3 = ± 3.4641

step-by-step explanation: