Question 966913
v = current value of Maddys house
p = projected value
t = timr

current value minus the 11% lost of value per year = the projected value
v - 11%t = p (REMEMBER TIME IS IN YEARS IF YOU WANT TO CALCULATE FOR A NUMBER OF MONTHS YOU WILL NEED TO / BY 12)

Rewrite equation

Simply 11% divide by 2 = 5.5% decrease per month

therefore

v - 5.5%t = p (REMEMBER TIME IS IN MONTHS IF YOU WANT TO CALCULATE FOR A NUMBER OF YEARS YOU WILL NEED TO * BY 12)