Subtract 110 and 8.75 and you get 101.25 then divide that by 9 and you get 11.25
Using the formula a² + b² = c² but reversing it to c² - b² = x² where x replaces the a for comprehension reasons
so this is the formula
c² - b² = x²
insert the numbers on the triangle in the picture
21² - 8² = 377
since 377 is squared and not the side length, we need to square root it to find x
√377 = 19.4~
Answer: x = 19.4
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
