50-30=20 кг
ответ:20 кг смородины собрали
((3/8 - 5/6) : 3/4 + (-3/8 - 7/20) : 1 9/20) * 1/50 = - 1/45
1) 3/8 - 5/6 = 9/24 - 20/24 = - 11/24
2) - 11/24 : 3/4 = (-11/24) * 4/3 = - (11*1)/(6*3) = - 11/18
3) - 3/8 - 7/20 = - 15/40 - 14/40 = - 29/40
4) - 29/40 : 1 9/20 = - 29/40 : 29/20 = - 29/40 * 20/29 = - 20/40 = - 1/2
5) - 11/18 + (-1/2) = - 11/18 - 9/18 = - 20/18
6) - 20/18 * 1/50 = - (2*1)/(18*5) = - 2/90 = - 1/45
513 ÷ 57 = 9
х = 387 ÷ 9
х = 43
387 ÷ 43 = 513 ÷ 57
387 ÷ 43 = 9
9 = 9
Ответ: х = 43
72 : 60% • 100% = 120
84 : 60% • 100% = 140
102 : 60% • 100% = 170
114 : 60% • 100% = 190
42 : 60% • 100% = 70