16 + { 400 : [ 200 - 180 ]

16 + { 400 : 20 }

16 + 20

=36

Trong bài có vài đoạn mình rút ngắn lại nha.

a) 400 - 5x = 200

5x = 200

x = 40

b) 250 : x + 10 = 20

250 : x = 10

x = 25

c) 96 - 3 ( x + 8 ) = 42

3 ( x + 8 ) = 54

( x + 8 ) = 54 : 3

x + 8 = 18

x = 18 - 8

x = 10

d) 36 : ( x - 5 ) = 2²

36 : ( x - 5 ) = 4 

x - 5 = 36 : 4

x - 5 = 9

x = 9 + 5 

x = 14

e) 15 x 5 ( x - 35 ) - 525 = 0

75 ( x - 35 ) - 525 = 0

75 ( x - 35 ) = 525

x - 35 = 7 

x = 7 + 35

x = 42

f) [ 3 x ( 70 - x ) + 5 ] : 2 = 46

[ 3 x ( 70 - x ) + 5 ] = 92

3 x ( 70 - x ) = 87

70 - x = 87 : 3

70 - x = 29 

x = 41

16:Sửa đề: \(\frac12x+\frac16\left(x-2\right)=\frac34-2x\)

=>\(\frac12x+\frac16x-\frac26=\frac34-2x\)

=>\(\frac46x-\frac13=\frac34-2x\)

=>\(\frac23x+2x=\frac34+\frac13\)

=>\(\frac83x=\frac{9}{12}+\frac{4}{12}=\frac{13}{12}\)

=>\(x=\frac{13}{12}:\frac83=\frac{13}{12}\times\frac38=\frac{13}{4\times8}=\frac{13}{32}\)

19: \(\frac{5}{12}x+3=\frac13-\frac{7}{12}x\)

=>\(\frac{5}{12}x+\frac{7}{12}x=\frac13-3\)

=>\(\frac{12}{12}x=\frac13-\frac93=-\frac83\)

=>\(x=-\frac83\)

20: \(\frac12x+\frac52=\frac72x-\frac34\)

=>\(\frac12x-\frac72x=-\frac34-\frac52\)

=>\(-3x=-\frac34-\frac{10}{4}=-\frac{13}{4}\)

=>\(3x=\frac{13}{4}\)

=>\(x=\frac{13}{4}:3=\frac{13}{12}\)

3x-16:2^3=4.4^2

3.x-16:8=4.16

3.x-2=64

3.x=66

x=22

`#3107`

`3x - 16 \div 2^3 = 4*4^2`

`=> 3x - 2^4 \div 2^3 = 2^2 * (2^2)^2`

`=> 3x - 2 = 2^2 * 2^4`

`=> 3x - 2 = 2^6`

`=> 3x = 2^6 + 2`

`=> 3x = 64 + 2`

`=> 3x = 66`

`=> x = 66 \div 3`

`=> x = 22`

Vậy, `x = 22.`

1: \(347\cdot2^2-2^2\cdot\left(216+184\right):8\)

\(=347\cdot4-4\cdot400:8\)

\(=347\cdot4-4\cdot50=4\cdot\left(347-50\right)=4\cdot297=1188\)

2: \(132-\left\lbrack116-\left(132-128\right)^2\right\rbrack\)

\(=132-\left\lbrack116-4^2\right\rbrack\)

=132-(116-16)

=132-100

=32

3: \(16:\left\lbrace400:\left\lbrack200-\left(37+46\cdot3\right)\right\rbrack\right\rbrace\)

=16:{400:[200-(37+138)]}

=16:{400:[200-175]}

=16:{400:25}

=16:16

=1

4: \(\left\lbrace184:\left\lbrack96-124:31\right\rbrack-2\right\rbrace\cdot3651\)

\(=\left\lbrace\frac{184}{96-4}-2\right\rbrace\cdot3651\)

=(184:92-2)*3651

=0

5: \(46-\left\lbrack\left(16+71\cdot4\right):15\right\rbrack-2\)

=46-[(16+284):15]-2

=46-300:15-2

=46-20-2

=46-22

=24

6: \(3^3\cdot18+72\cdot4^2-41\cdot18\)

\(=18\left(3^3-41\right)+72\cdot16\)

\(=18\cdot\left(27-41\right)+18\cdot64\)

=18(-14+64)

=18*50

=900

7: \(\left(56\cdot46-25\cdot23\right):23\)

\(=56\cdot\frac{46}{23}-25\)

=112-25

=87

8: \(\left(28\cdot54+56\cdot36\right):21:2\)

\(=18\cdot28\left(3+2\cdot2\right):42\)

\(=18\cdot\frac{28}{42}\cdot7=18\cdot\frac23\cdot7=12\cdot7=84\)

9: \(\left(76\cdot34-19\cdot64\right):\left(38\cdot9\right)\)

\(=\frac{19\cdot\left(4\cdot34-64\right)}{38\cdot9}=\frac{4\cdot34-64}{9\cdot2}=\frac{4\cdot\left(34-16\right)}{18}=4\)

10: \(\left(2+4+6+\cdots+100\right)\cdot\left(36\cdot333-108\cdot111\right)\)

\(=\left(2+4+6+\cdots+100\right)\cdot36\cdot111\left(3-3\right)\)

=0

11: \(\left(5\cdot4^{11}-3\cdot16^5\right):4^{10}\)

\(=\left(5\cdot4^{11}-3\cdot4^{10}\right):4^{10}\)

\(=5\cdot\frac{4^{11}}{4^{10}}-3\cdot\frac{4^{10}}{4^{10}}\)

=20-3

=17

12: \(\frac{7256\cdot4375-725}{3650+4375\cdot7255}=\frac{7255\cdot4375+4375-725}{7255\cdot4375+3650}\)

\(=\frac{7255\cdot4375+3650}{7255\cdot4375+3650}\)

=1

vip đây

mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm

285.x+115.x=400

(285+115).x=400

400.x=400

x=\(\dfrac{400}{400}\)

x=1

x*(285+115)=400

x*400=400

x=400:400

x=1

chúc em học tốt

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!