1) 36/5:12/5=36/12=3
2) 3=0,9:х
3=9/10/х
3=10х/9
3/9=10х/9
3=10х
Х=3 целых 1/3
<span>1) 54-18= 36(осталось). 2) 36+54= 90(км). Ответ: 90 км</span>
номер 2
12+14+16+18+20+22+24+26+28+30+32+34+36+38+40=390
(2/3х + 1/8х) * 24 = 38,
16/24х + 3/24х = 38 : 24,
19/24х = 38/24,
х = 38/24 : 19/24,
х = 38/24 * 24/19,
х = 2,
Проверка:
(2/3*2 + 1/8*2) * 24 = 38,
(4/3 + 1/4) * 24 = 38,
(16/12 + 3/12) * 24 = 38,
19/12 * 24 = 38,
19*2 = 380
38 = 38
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