Odpowiedź :
123% - 1230zl
100% - x
x = 100% * 1230zl / 123% = 1000zl
1000zl - 200zl = 800zl
800zl - 100%
y - 120%
y= 120% * 800zl / 100% = 960zl
123% - 1230zl
100% - x
x = 100% * 1230zl / 123% = 1000zl
1000zl - 200zl = 800zl
800zl - 100%
y - 120%
y= 120% * 800zl / 100% = 960zl