Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(=\left(152-148\right)+\left(144-140\right)+\left(136-132\right)+\left(128-124\right)+\left(120-116\right)+\left(112-108\right)+\left(104-100\right)\\ =4+4+4+4+4+4+4=28\)
☠ 
Tính nhanh các tổng sau:
a) 2 + 5 + 8 + 11 + 14 + 17 + 20 + 23 + 26 + 29
= ( 2+ 8 ) + ( 5 + 20) + ( 11 + 29 ) + ( 14 + 26 ) + ( 17 + 23 )
= 10 + 25 + 40 + 40 + 40
= 35 + 120
= 155
b) 120 + 116 + 112 + 108 + 104 + 100 + 96 + 92 + 88 + 84 + 80
= ( 120 + 80 ) + ( 116 + 84 )+ ( 112 + 88 ) + ( 108 + 92 ) + ( 104 + 96 ) + 100
= 200 + 200 + 200 + 200 + 200 + 100
= 200 x 5 + 100
= 1100
B = 1 2 + 1 6 + 1 12 + 1 20 + 1 30 + 1 42 + 1 56 + 1 72 + 1 90
B = 1 1.2 + 1 2.3 + 1 3.4 + 1 4.5 + 1 5.6 + 1 6.7 + 1 7.8 + 1 8.9 + 1 9.10
= 1 − 1 2 + 1 2 − 1 3 + 1 3 − 1 4 + 1 4 − 1 5 + ... + 1 9 − 1 10
= 1 + − 1 2 + 1 2 + − 1 3 + 1 3 + − 1 4 + 1 4 + − 1 5 + 1 5 + ... + − 1 9 + 1 9 − 1 10
= 1 − 1 10 = 9 10
\(1+2+3+...+2005+2006=\left[\left(2006-1\right):1+1\right].\left(2006+1\right):2.\)
\(=2006.2007:2\)
\(=2013021\)
\(5+10+...+2000+2005=\left[\left(2005-5\right):5+1\right].\left(2005+5\right):2.\)
\(=401.2010:2\)
\(=403005\)
\(140+136+....+64+60=\left[\left(140-60\right):16+1\right].\left(140+60\right):2.\)
\(=6.200:2\)
\(=600\)
Giải;
1) \(347.222-222.\left(216+184\right):8\)
\(=347.222-222.400:8\)
\(=347.222-222.50\)
\(=222.\left(347-50\right)\)
\(=222.297\)
\(=65934\)
2) \(132-\left[116-\left(132-128\right).22\right]\)
\(=132-\left[116-4.22\right]\)
\(=132-\left[116-88\right]\)
\(=132-28\)
\(=104\)
3) \(16:\left\{400:\left[200-\left(37+46.3\right)\right]\right\}\)
\(=16:\left\{400:\left[200-\left(37+138\right)\right]\right\}\)
\(=16:\left\{400:\left[200-175\right]\right\}\)
\(=16:\left\{400:25\right\}\)
\(=16:16\)
\(=1\)
4) \(\left\{184:\left[96-124:31\right]-2\right\}.3651\)
\(=\left\{184:\left[96-4\right]-2\right\}.3651\)
\(=\left\{184:92-2\right\}.3651\)
\(=\left\{2-2\right\}.3651\)
\(=0.3651\)
\(=0\)
5) \(46-\left[\left(16+71.4\right):15\right]-2\)
\(=46-\left[\left(16+284\right):15\right]-2\)
\(=46-\left[300:15\right]-2\)
\(=46-20-2\)
\(=24\)
6) \(3^3.18+72.4^2-41.18\)
\(=18.\left(27-41\right)+72.16\)
\(=18.-14+1152\)
\(=-252+1152\)
\(=900\)
Giải: (tiếp)
7) \(\left(56.46-25.23\right):23\)
\(=\left(2576-575\right):23\)
\(=2001:23\)
\(=87\)
8) \(\left(28.54+56.36\right):21:2\)
\(=\left(1512+2016\right):21:2\)
\(=3528:21:2\)
\(=84\)
9) \(\left(76.34-19.64\right):\left(38.9\right)\)
\(=\left(2584-1216\right):342\)
\(=1368:342\)
\(=4\)
10) \(\left(2+4+6+...+100\right).\left(36.333-108.111\right)\)
\(=\left(2+4+6+...+100\right).\left(11988-11988\right)\)
\(=\left(2+4+6+...+100\right).0\)
\(=0\)
11) \(\left(5.4^{11}-3.16^5\right):4^{10}\)
\(=5.4^{11}:4^{10}-3.16^5:4^{10}\)
\(=5.4-3.1\)
\(=20-3\)
\(=17\)
12) \(7256.4375-725:3650+4375.7255\)
\(=4375.\left(7256+7255\right)-\dfrac{29}{146}\)
\(=4375.14511-\dfrac{29}{146}\)
\(=63485624,8\)
Câu 12 ko chắc!
152 - 148 + 144 - 140 + 136 - 132 + 128 - 124 + 120 - 116 + 112 - 108 + 104 - 100=
= ( 152 -132 ) - ( 148 - 128 ) + ( 144 - 124 ) - ( 140 - 120 ) + ( 136 - 116 ) - ( 132 - 112 ) - ( 124 - 104 )
= 20 - 20 + 20 - 20 + 20 - 20 - 20
= -20
HOk tốt!!!!!!!!
mình ko ghi đề ra đâu bạn nhé
= 4+4+4+4+4+4+4
= 28