The cost of a large flat screen tv is decreasing 20% per year.

if a 50 inch flat screen cost $1200, what will it cost in 3 years

Let x be the old price

X = 1200$

The price decreased 20% after 1 year to become price y:

Y = 0.8x

= 0.8 (1200)

= 960$

In the year after y also decreased 20% to be price y':

Y' = 0.8y

= 0.8 (960)

= 768 $

The price y' then decreased 20% to become price y'':

Y'' = 0.8 y'

= 0.8 (768)

= 614.4 $

Then the price will be 614.4 $ after 3 years

614.4$

Step-by-step explanation:

We know that every year, the value depreciates 20%. Thus, the new value at the end of each year is equal to 80% of the old value. As a result, the value in 3 years is equal to multiplying the original value (1200) by 80% 3 times. As 80%=0.8, 1200 * (0.8) ^3=614.4 is our answer