1,75 * 7/9 * (0,85 + 4/35) + 7,511 : 3,7 * 10/291,75 * 7/9 = 7/4 * 7/9 = 49/360,85 + 4/35 = 17/20 + 4/35 = (119 + 16) / 140 = 135/140 = 27/2849/36 * 27/28 = 1323/10087,511 : 3,7 = 2,03 = 2 3/100 = 203/100203/100 * 10/29 = 7/101323/1008 + 7/10 = 2 63/5040
83x-57x=305-19
26x=286
x=11
1) 1 час = 60 мин. 1/10 = 60÷10×1. 1/10 = 6 минут.
2) 3/4 часа = (60÷4)×3 = 15×3=45
3) 1/3 27 = 27÷3×1 = 9×1 = 9
4) 3/4 60 = 60÷4×3 = 15×3= 45