1) (-1 5/11+(-6 6/11))+(-3/7 + (-1 4/7))=-10
(-1 5/11+(-6 6/11)=-1 5/11-6 6/11=-8
-3/7 -1 4/7=-2
-8+(-2)=-8-2=-10
2) (-5 9/17+(-4 8/17))+(-4/15+(-4 14/15))=-15 1/5
-5 9/17+(-4 8/17)=-5 9/17-4 8/17=-10
-4/15+(-4 14/15)=-4/15-4 14/15=-5 1/5
-10+(-5 1/5)=-10-5 1/5=-15 1/5
3) (-1 2/7+(-3 5/7))+(-8 5/9)=-13 5/9
-1 2/7+(-3 5/7)=-1 2/7-3 5/7=-5
-5+(-8 5/9)=-5-8 5/9=-13 5/9
4) (-3 2/3) + (-1 4/9+(-6 5/9))=-11 2/3
-1 4/9+(-6 5/9)=-1 4/9-6 5/9=-8
-3 2/3+(-8)=-3 2/3-8=-11 2/3
Пошаговое объяснение:
1) (2 3/8 -х) / 3 1/4 + 2 13/15 = 3 1/6
(19/8 - х) / 13/4 + 43/15 = 19/6 19/26 - 4/13 *х + 43/15 = 19/6
19/26 +43/15 -19/6 = 4/13* х 285/390 + 598/390 - 1235/390 =4/13 * х
-352/390 = 4/13 *х х = -44/15 = -2 14/15
2) 4 1/2 - 5 1/3 / (20х -14 2/3) = 1 5/6 9/2 -16/3 / (20х -44/3) = 11/6
16/3 / (20х -44/3) = 11/6 - 9/2 16/3 / (20х -44/3) = - 16/6 , разделим правую и левую часть уравнения на 16/6 2 /(20х - 44 /3) = -1 2 = -20х +44/3
20х = 44/3 -2 20х =44/3 - 6/3 20х = 38/3 60х = 38 х = 38/60 х = 19/30
ответ: Можно составить 120 шифров