it's hard to explain, but the 10% increase isn't referring to an additional 10% of tax on the houses but an increase of 10% of the 10%.
.1 x 1.1 = .11
10% x 1.1 = 11%
then I just plugged in numbers
100,000 x .1 = 10,000
90,000 x .11 = 9,900
decrease of 1%
Still don't understand the wording too well; can someone elaborate on this?
Lets say value of the property is $V and tax on that $V is T% . Hence the tax amount on the $V is = $VT
now value is decreased by 10 % ( 0.9V) and tax increased by 10% ( 1.1 T) , the new tax amount is 0.9V*1.1T = 0.99VT
Hence new tax amount decreases by 0.01VT ( i.e 1% the original)