№123.
А) (а+8)•40=40а+320 Б) (12-b)•7=84-7b В) 12•(6+с)=72+12c Г) 10•(d-8)=10d-80
№124.
А) 1495•211+211•1505=211*(1495+1505)=211*3000=633000
Б) 3249•627-627•3049= 627*(3249-3049)=627*200=125400
В) 934•124-617•124+683•124=124*(934-617+683)=124*(934+683-617)=
=124*(1617-617)=124*1000=124000
№125.
А) 24a+16a=40a E) 12z-z=11z Ж)135n+286n-121n=300n
№126
А) 37m+63m=100m
если m=37 100*37=3700
если m=8 100*8=800
№127
А) 34x+17x=1173
51х=1173
х=1173:51
х=23
Б) 48y-25y=437
23у=437
у=437:23
у=19
1.
а) 7 7/9 - 4 1/12 = 70/9 - 49/12 = 280/36 - 147/36 = 133/36 = 3 25/133
б) 4 2/3 + 5 3/4 = 14/3 + 23/4 = 56/12 + 69/12 = 125/12 = 10 5/12
в) 5 1/5 - 1 2/3 = 26/5 - 5/3 = 78/15 - 25/15 = 53/15 = 3 8/15
г) 12 - 3 3/7 = 84/7 - 24/7 = 60/7
д) 4,75 - 1 1/8 = 4,75 - 1,125 = 3,625
е) 0,7 + 2 7/15 = 7/10 + 37/15 = 21/30 + 74/30 = 95/30 = 19/6
2.
3/4 = 18/24
7/8 = 21/24
5/6 = 20/24
7/12 = 14/24
11/24 = 11/24
1/2 = 12/24
2/3 = 16/24
11/24 < 12/24 < 14/24 < 16/24 <18/24 < 20/24 < 21/24
Значит, 11/24 < 1/2 < 7/12 < 2/3 < 3/4 < 5/6 < 7/8.
ответ: 11/24, 1/2, 7/12, 2/3, 3/4, 5/6, 7/8.
3.
1) (118 7/12 + 4 5/9) - 18 7/12 = 118 7/12 - 18 7/12 + 4 5/9 = 100 + 4 5/9 = 104 5/9
2) 132 8/15 - (2 8/15 + 4 3/7) = 132 8/15 - 2 8/15 - 4 3/7 = 130 - 4 3/7 = 125 4/7
3) (146 5/17 + 8 5/19) - 26 5/17 = 146 5/17 - 26 5/17 + 8 5/19 = 120 + 8 5/19 = 128 5/19
4) 158 8/21 - (26 8/21 + 30 7/11) = 158 8/21 - 26 8/21 - 30 7/11 = 132 - 30 7/11 = 101 4/11
Слава УСРАИНЕ!