how to simplify it?

[guest]

this: z(1 + x/100)(1 - y/100) to this:

(10,000z + 100z(x - y) - xyz) /10,000

?

[Guest]

z(1 + x/100)(1 - y/100) [A*B*C from]
= z ((100+x)/100) ((100-y)/100) [ Simplify B and C]
= z/10000 ((100+x) (100-y)) [X/100 * Y/100 = 1/10000 * XY]
= z/10000 (10000 +100(x-y) -xy) [(a+b)(a-c) = a*a +(b-c)*a + b*(-c). NOTE: (a-b)(a-c) = a*a + (-b-c)*a + (-b)*(-c)]
= (10000z +100z(x-y) -xyz)/10000 [z/10000 *(a+b) = (az + bz)/10000].

[guest]

how do you get from this (1 + x/100)(1 - y/100) to (100+x)/100)(100-y)/100) ?

[guest]

ok, i figured it out...i had a cloud over my head..