Bonjour;

[(242,78 -199)/199]*100

=>22%

11

HT + TVA = TTC

HT + HT x taux TVA = TTC

TTC = 2,50 + 2,50x5,5%

12

HT + TVA = TTC

HT + HT x 20% = 298,80

HT(1+20%) = 298,80

HT = 298,80 : 1,20

13

199 + 199 x taux = 242,78

taux = (242,78 - 199)/199

14

agrandissement = [(31,5 - 14)/14] x 100