Question 252886
If we increase a by 10% we will get a+0.1a
If we decrease b by 10% we will have b-0.1b

(a+0.1a)/(b-0.1b)=1
1.1a=0.9b  multiply each side by 10
11a=9b  divide each side by b and also 11
a/b=9/11

CK
(9+0.9)/(11-1.1)=9.9/9.9=1

Hope this helps ---ptaylor