1 НАЙДИ Творение 2/3*8/13 12/49*7/24 1 4/35*1 2/13 2 5/11*2 4/9

1) 2/3 * 8/13 = (2 * 8)/(3 * 13) = 16/36;

12/49 * 7/24 = (12 * 7)/(49 * 24) = 1/14;

1 4/35 * 1 2/13 = 39/35 * 15/13 = (39 * 15)/(35 * 13) = (3 * 3)/7 = 9/7;

2 5/11 * 2 4/9 = 27/11 * 22/9 = (27 * 22)/(11 * 9) = 3 * 2 = 6;

2 4/5 * 10 = 14/5 * 10 = 14 * 2 = 28;

2) а) 21/16 * (63/7 - 15/7) = 21/16 * 48/7 = 9;

б) (88/10 * 10/16 - 305/100) * 14/10 = (110/20 - 61/20) * 14/10 = 49/20 * 7/5 = 343/100;

3) 2 4/7 * (1 - 8/9) = 18/7 * 1/9 = 2/7;

4) 2 3/4 * x + 1 1/16 * x = (2 * 4 + 3)/4 * х + (1 * 16 + 1)/16 * х = 11/4 * х + 17/16 * х = х * (11/4 + 17/16) = х * (44/16 + 17/16) = х * 61/16;

При х = 32/45:

32/45 * 61/16 = (32 * 61)/(45 * 16) = (2 * 61)/45 = 122/45.