х * 18 = 90 х : 12 = 7
х = 90 : 18 х = 7 * 12
х = 5 х = 84
72 : х = 12
х = 72 : 12
х = 6
26 * х = 52
х = 52 : 26
х = 2
14 * х = 56
х = 56 : 14
х = 4
23 * х = 92
х = 92 : 23
х = 4
84 : х = 2
х = 84 : 2
х = 42
Пошаговое
объяснение:
10¹ = 10
10^0 = 1; 10^-1 = 1/10; 10^-2 = 1/10² = 1/100;
10^-3 = 1/10³ = 1/1000
10^-4 = 1/10⁴ = 1/10000
а)
3*1 + 2*1/10 + 5*1/100 + 6*1/1000
3 + 2/10 + 5/100 + 6/1000 = 3 + 200/1000 + 50/1000 + 6/1000 =
3 + 256/1000 = 3 + 32/125 = 3. 32/125 = 3,256
б)
4*1/100 + 5*1/10 + 7*1 =
4/100 + 5/10 + 7 =
1/25 + 1/2 + 7 =
2/50 + 25/50 + 7 =
7. 27/50 = 7,54
в)
4*10 + 7*1 + 6*1/100 + 5*1/1000 =
40 + 7 + 6/100 + 5/1000 = 47 + 3/50 + 1/200 =
47 + 12/200 + 1/200 =
47 + 13/200 = 47. 13/200 = 47,065
г)
1 + 6*1/10 + 4*1/100 + 5*1/10000 =
1 + 6/10 + 4/100 + 5/10000 =
1 + 6/10 + 4/100 + 1/2000 = 1 + 1200/2000 + 80/2000 + 1/2000 =
1 + 1281/2000 = 1. 1281/2000 = 1,6405