x : 7/20 (7 supra 20) = 12/13 (12 supra 13).Va rog este URGENT !!!

Răspuns :

x÷7/20=12/13
x×20/7=12/13
20/7x=12/13
7/20×20/7x=7/20×12/13
x=7/5×3/13
x=21/65..........ver; 21/65÷7/20=12/13, 21/65×20/7=12/13, 3/13×4=12/13,
12/13=12/13......./bara inseamna supra