a) 295 - (31 - 2² x 5)²

= 295 - (31 - 4 x 5)²

= 295 - (31 - 20)²

= 295 - 11²

= 295 - 121

= 174

b) 7⁹ : 7⁷ - 3² + 2³ x 5²

= 7² - 9 - 8 x 25

= 49 - 9 - 8 x 25

= 40 - 200

= -160

c) 1200 : 2 + 6² x 2¹ + 18

= 600 + 36 x 2 + 18

= 600 + 72 + 18

= 600 + 90

= 690

d) 151 - 2⁹¹ : 2⁸⁸ + 1² x 3

= 151 - 2³ + 1 x 3

= 151 - 8 + 1 x 3

= 151 - 8 + 3

= 151 - 11

= 140

e) 2³⁸ : 2³⁶ + 5¹ : 3² - 7²

= 2² + 5 : 9 - 49

= 4 + 5 : 9 - 49

= 9 : 9 - 49

= 1 - 49

= -48

Học tốt!!!

\(\left(\frac{3}{4}+\frac{2}{11}-\frac{8}{13}\right)+\left(\frac{1}{4}-\frac{5}{13}\right)\)

\(=\frac{3}{4}+\frac{2}{11}-\frac{8}{13}+\frac{1}{4}-\frac{5}{13}\)

\(=\left(\frac{3}{4}+\frac{1}{4}\right)+\frac{2}{11}-\left(\frac{8}{13}+\frac{5}{13}\right)\)

\(=1+\frac{2}{11}-1\)

\(=\frac{2}{11}\)

\(\left(\frac{9}{53}+\frac{21}{31}\right)+\left(\frac{44}{53}-\frac{16}{7}\right)+\frac{10}{31}\)

\(=\frac{9}{53}+\frac{21}{31}+\frac{44}{53}-\frac{16}{7}+\frac{10}{31}\)

\(=\left(\frac{9}{53}+\frac{44}{53}\right)+\left(\frac{21}{31}+\frac{10}{31}\right)-\frac{16}{7}\)

\(=1+1-\frac{16}{7}\)

\(=2-\frac{16}{7}\)

\(=\frac{14}{7}-\frac{16}{7}\)

\(=\frac{-2}{7}\)

#)Giải :

\(200-18:\left(372:3x-1\right)-28=166\)

\(\Leftrightarrow200-18:\left(372:3x-1\right)=194\)

\(\Leftrightarrow18:\left(372:3x-1\right)=6\)

\(\Leftrightarrow372:3x-1=3\)

\(\Leftrightarrow3x-1=124\)

\(\Leftrightarrow3x=125\)

\(\Leftrightarrow x=\frac{125}{3}\)

200 - 18 : (372 : 3 . x - 1) - 28 = 166

=> 200 - 18 : (372 : 3.x - 1)     = 166 + 28

=> 200 - 18 : (372 : 3.x) - 1)    = 194

=>          18 : (372 : 3.x - 1)     = 200 - 194

=>          18 : (372 : 3.x - 1)     = 6

=>                  372 : 3.x  - 1      = 18 : 6

=>                  372 : 3.x - 1       = 3

=>                    372 : 3.x          = 3 + 1

=>                    372 : 3.x          = 4

=>                             3.x          = 372 : 4

=>                             3.x          = 93

=>                                x          = 93 : 3

=>                                x          = 31

#)Next:

\(\left(100-99+98-97+...+2-1\right):50+2010-12x=91\)

\(\Leftrightarrow\left[\left(100-99\right)+\left(98-97\right)+...+\left(2-1\right)\right]:50+2010-12x=91\)

\(\Leftrightarrow\left[1+1+...+1\right]:50+2010-12x=91\)

\(\Leftrightarrow50:50+2010-12x=91\)

\(\Leftrightarrow1+2010-12x=91\)

\(\Leftrightarrow2011-12x=91\)

\(\Leftrightarrow12x=1920\)

\(\Leftrightarrow x=160\)

a: \(3^8:3^4+2^2\cdot2^3\)

=81+32

=123

b: \(3\cdot4^2-2\cdot3^2\)

\(=48-18\)

=30

a, 3⁸: 3⁴+ 2². 2³

= 3^8-4 + 2²⁺³

= 3⁴ + 2⁵

= 81 + 32

= 113

b,  3 . 4²- 2 . 3²

= 3 . 16 - 2 . 9

= 48 - 18

= 30

c,  84 : 4 + 3⁹: 3⁷+ 5⁰

= 84 : 4 + 3² + 1

= 84 : 4 + 9 + 1

= 21 + 9 + 1

= 31

d,  295 - ( 31 - 2² . 5)²

= 295 - ( 31 - 4 . 5 )²

= 295 - ( 31 - 20 )²

= 295 - 11²

= 295 - 121

= 174

e, 500 - {5[409 - (2³ . 3 - 21)² ] + 10³ } : 15

= 500 -  {5[409 - (8 . 3 - 21)² ] + 10³ } : 15

= 500 -  {5[409 - (24 - 21)² ] + 10³ } : 15

= 500 -  {5[409 - 3² ]+ 10³ } : 15

= 500 - {5[409 - 9 ]+ 10³ } : 15

= 500 - {5 . 400 + 1000 } : 15

= 500 - {2000 + 1000} : 15

= 500 - 3000 : 15

= 500 - 200

= 300

g, 5³ . 2 - 100 : 4 + 2³ . 5

= 125 . 2 - 100 : 4 + 8 . 5

= 250 - 25 + 40

= 225 + 40

= 265

h, 205 - [1200 - (4² - 2 . 3)³ ] : 40

= 205 - [ 1200 - ( 16 - 2 . 3 )³ : 40

= 205 - [ 1200 - ( 16 - 6 )³  ] : 40

= 205 - [ 1200 - 10³ ] : 40

= 205 - [ 1200 - 1000 ] : 40

= 205 - 200 : 40

= 205 - 5

= 200

Đây nha bạn!!!

3: =231+26-209-26=22

4: =19(25+30+45)=19x100=1900

5: =-50+19+143+79-25-48

=-75+95+98

=98+20=118

Khiếp

2 . 53 . 27 + 6 . 9 . 87 - 3 . 18 . 40 
= 2. 53 . 9 . 3 + 2. 3 .9 .87 - 3 .2 .9 .40
= 54.53+54.87-54.40
=54(53+87-40)
=54. 100=5400

12 . 25 + 29 . 25 + 59 . 25 
= 25 . ( 12+29+59)
=25 . 90
=2250

43 . 37 + 93 . 43 + 57 . 61 + 69 . 57 
= 43.(37+93)+57(61+69)
=43.130+57.130
=130.(43+57)
=130.100
=13 000

12 . 53 + 53 . 172 - 53 
=53(12+172-1)
=53.184
=9752

35 . 54 + 35 . 58 + 65 . 75 + 65 . 45 
=35(54+58)+65(75+45)
=35.112+65.120
=3920+7800
=11720

39 . 8 + 70 . 3 + 31 . 8 
=8(39+31)+70.3
=8.70+70.3
=70.(8+3)
=70.11
=770

2 . 53 . 27 + 6 . 9 . 87 - 3 . 18 . 40

= ( 2 . 27 ) . 53 + ( 6 . 9 ) . 87 - ( 3 . 18 ) . 40

= 54 . 53 + 54 . 87 - 54 . 40

= 54(53+87-40)

= 5400

12 . 25 + 29 . 25 + 59 . 25

= 25( 12 + 29 + 59 )

= 2500

43 . 37 + 93 . 43 + 57 . 61 + 69 . 57

= 43( 37 + 93 ) + 57(61 + 69 )

= 5590 + 7410

= 13000

12 . 53 + 53 . 172 - 53 

= 53( 12 + 172 ) - 53

= 9752 - 53

= 9699

35 . 54 + 35 . 58 + 65 . 75 + 65 . 45

= 35( 54 + 58 ) + 65( 75 + 45 )

= 3920 + 7800

= 11720

a,  -3/4 + 3/7 + -1/4 + 4/9 + 4/7

=\(\left(\frac{-3}{4}+\frac{-1}{4}\right)+\left(\frac{3}{7}+\frac{4}{7}\right)+\frac{4}{9}\)

=\(-1+1+\frac{4}{9}\)

=\(\frac{4}{9}\)

b, -7/9 x 4/11 + -7/9 x 7/11 + 5 và 7/9 

\(=\frac{7}{9}x\frac{-4}{11}+\frac{7}{9}x\frac{-7}{11}+5x\frac{7}{9}\)

\(=\frac{7}{9}x\left(\frac{-4}{11}+\frac{-7}{11}+5\right)\)

\(=\frac{7}{9}x4\)

\(=\frac{28}{9}\)

c, ( 21/31 + 2013/6039 ) - ( 44/53 - 10/31) - /53