Ответ: 4; 3 5/12.
Пошаговое объяснение:
3) 2 1/3 + 4 1/10 : (2 7/15 - 5/12) * 5/6 =
= (2*3+1)/3 + (4*10+1)/10 : ((2*15+7)/15 - 5/12)) * 5/6 =
= 7/3 + 41/10 : (37/15 - 5/12) * 5/6 =
= 7/3 + 41/10 : (37*4/15*4 - 5*5/12*5) * 5/6 =
= 7/3 + 41/10 : (148/60 - 25/60) * 5/6 =
= 7/3 + 41/10 : (148-25)/60 *5/6 =
= 7/3 +41/10 : 123/60 * 5/6 =
= 7/3 +41/10 : 41*3/20*3 * 5/6 =
= 7/3 + 41/10 : 41/20 * 5/6 =
=7/3 + 41/10 * 20/41 * 5/6 =
= 7/3 + 41*20/10*41 * 5/6 = 7/3 + 20/10 * 5/6 =
= 7/3 + 10*2/10*1 *5/6 = 7/3 + 2/1 * 5/6 =
= 7/3 + 2*5/1*6 = 7/3 + 10/6 = 7/3 + 5*2/3*2 =
= 7/3 + 5/3 = (7+5)/3 = 12/3 = 4
Ответ: 4.
4) 4 5/12 - 1 1/2 : (2 1/6 + 8/15) * 1 4/5 =
= (4*12+5)/12 - (1*2+1)/2 : (( 2*6+1)/6 + 8/15)) * (1*5+4)/5 =
= 53/12 - 3/2 : (13/6 + 8/15) * 9/5 =
= 53/12 - 3/2 : (13*5/6*5 + 8*2/15*2) * 9/5 =
= 53/12 - 3/2 : (65/30 + 16/30) * 9/5 =
= 53/12 - 3/2 : (65+16)/30 * 9/5 = 53/12 - 3/2 : 81/30 * 9/5 =
= 53/12 - 3/2 : 27*3/10*3 * 9/5 = 53/12 - 3/2 : 27/10 * 9/5 =
= 53/12 - 3/2 * 10/27 * 9/5 = 53/12 - 3*10/2*27 * 9/5 =
= 53/12 - 3*5*2/2*9*3 * 9/5 = 53/12 - 5/9 * 9/5 =
= 3/12 - 5*9/9*5 = 53/12 - 1 = 53/12 - 12/12 = (53-12)/12 =
= 41/12 = (36+5)/12 = 36/12 + 5/12 = 3 + 5/12 =
= 3 5/12 (или 3 целых 5/12)
Ответ: 3 5/12.