Вычислите а) 5,7\12+1,1\3 б) 6,3\50-3,13\75 в)5,6\55+3,9\44-4,7\22

а) 5,7 / 12 + 1,1 / 3 = 43/72.

1). 5,7 / 12 = 5 7/10 / 12 = 57/10 / 12 = 57/10* 1/12 = 57/120 = 19/40;

2). 1,1 / 3 = 1 1/10 / 3 = 11/10 / 3 = 11/30 * 1/3 = 11/90;

3) 19/40 + 11/90 = (19 * 9) / (40 * 9) + (11 * 4) / (90 * 4) = 171/360 + 44/360 = 215/360 = 43/72.

б) 6,3 / 50 - 3,13 / 75 = 158/185.

1). 6 3/10 / 50 = 63/10 * 1/50 = 63/500;

2). 3 13/100 / 75 = 313/100 * 1/75 = 313/7500;

3). 63/500 – 313/7500 = (63 * 15) / (500 * 15) – 313/7500 = 945/7500 – 313/7500 = 632/7500 = 158/1875

в) 5,6 / 55 + 3,9 / 44 - 4,7 / 22 = 51/2200.

1). 5 6/10 / 55 = 56/10 * 1/55 = 56/550 = 28/275;

2). 3 9/10 / 44 = 39/10 * 1/44 = 39/440;

3). 4 7/10 / 22 = 47/10 * 1/22 = 47/220;

4) 28/275 + 39/440 = (28 * 8) / (275 * 8) + (39 * 5) / (440 * 2) = 224/2200 + 195/2200 = 419/2200;

5). 419/2200 – 47/220 = 419/2200 – (47 * 10) / (220 * 10) = 419/2200 – 470/2200 = 51/2200.