Calculati respectand ordinea operatiilor:12/25× 20/27:16/15, (5/8+1/12):34/27, 12/11×33/30-10/9:20/21, (4/15-3/20):49/30, 14/15:10/21×45/1215506, 12/15+16/25÷8/1215506560,