câu 5:thực hiện phép tính sau một cách hợp lý

a) 463+318+137-118 

\(=(463+137)+(318-118)\) 

\(=600+200=800\)

-28:14/3

=-28.3/14

=-6

\(\left(-28\right):\dfrac{14}{3}=\left(-28\right)\cdot\dfrac{3}{14}=\dfrac{-7\cdot2\cdot2\cdot3}{7\cdot2}=-6\)

a) 405 - 15 x 2

= 405 - 30

= 375

b) 28 x 64 + 28 x 36

= 28 x ( 64 + 36 )

= 28 x 100

= 2800

c) ( -17  + ( -8 ) + 17 + ( -3 )

= [ ( -17 ) + 17 ] + [ ( -8 ) + ( -3 ) ] 

= 0 + ( -11 )

= -11

d) 235 - 4 x { 20 + [ 7² : ( 2³ - 1 ) ] }

= 235 - 4 x { 20 + [ 49 : ( 8 - 1 ) ] }

= 235 - 4 x { 20 + [ 49 : 7 ] }

= 235 - 4 x { 20 + 7 }

= 235 - 4 x 27

= 235 - 108

= 127

e) 8 - ( 3 - 7 )

= 8 - 3 + 7

= 5 + 7

= 12

g) 9 - ( -7 ) - 3

= 9 + 7 - 3

= 16 - 3

= 13

f)  ( -5 ) - ( 9 - 12 )

= ( -5 ) - 9 +12 

= -14 + 12

= -2

= 1512

chúc bạn học tốt

c) 3 x 25 x 8 + 4 x 37 x 6+ 2 x 12

= 3 x 8 x 25 + 4 x 6 x 37 + 2 x 12

= 24 x 25 + 24 x 37 + 24

= 24 x 25 + 24 x 37 + 24 x 1

= 24 x ( 25 + 37 + 1 )

= 24 x 63

= 1 512

~~ Hok T ~~

     \(\left(128-49\right)+\left(-51-28\right)\)

\(=128-49-51-28\)

\(=\left(128-28\right)-\left(49+51\right)\)

\(=100-100=0\)

43/57 . 2/6 . ( 630 - 315 . 2 )

= 43/57 . 2/6 . ( 630 - 630 )

= 43/57 . 2/6 . 0

= 43/57 . 0

= 0

45 . 16 - 17

= 720 - 17 

= 703

45 . 15 + 28

= 675 + 28 

= 703

104 . 68 - 36 . 52 = 52 + 52 . 68 - 36 . 52

                            = 52 ( 1 + 68 - 36 )

                            = 52 . 33

                             = 85

45 . 15 + 28 = 675 + 28 

                     = 703 

45 . 16 - 17 = 720 - 17 = 703

\(36:\left\{180:\left[2\cdot5^2-\left(5^3-3\cdot5\cdot7\right)\right]\right\}\)

\(=36:\left\{180:\left[2\cdot25-\left(125-15\cdot7\right)\right]\right\}\)

\(=36:\left\{180:\left[50-\left(125-105\right)\right]\right\}\)

\(=36:\left[180:\left(50-20\right)\right]\)

\(=36:\left(180:30\right)\)

\(=36:6\)

\(=6\)

\(=\dfrac{36}{180:\left[2\cdot25-5^3+15\cdot7\right]}=\dfrac{36}{180:30}=\dfrac{36}{6}=6\)

#)Giải :

Bài 1 :

\(A=\frac{15}{6.16}+\frac{15}{16.26}+\frac{15}{26.36}\)

\(A=3\left(\frac{5}{6.16}+\frac{5}{16.26}+\frac{5}{26.36}\right)\)

\(A=3\left(\frac{1}{6}-\frac{1}{16}+\frac{1}{16}-\frac{1}{26}+\frac{1}{26}-\frac{1}{36}\right)\)

\(A=3\left(\frac{1}{6}-\frac{1}{36}\right)\)

\(A=3.\frac{5}{36}\)

\(A=\frac{15}{36}\)

\(B=\frac{33}{6.16}-\frac{63}{16.26}+\frac{93}{26.36}\)

\(B=\frac{3.11}{6.16}-\frac{3.21}{16.26}+\frac{3.31}{26.36}\)

\(B=\frac{1}{2.16}.11+\frac{1}{2.16}.\frac{3.21}{13}+\frac{3.31}{26.36}\)

\(B=\frac{1}{32}.\frac{143-63}{13}+\frac{3.31}{26.12.3}\)

\(B=\frac{1}{32}.\frac{80}{13}+\frac{31}{36.12}\)

\(B=\frac{5}{26}+\frac{31}{26.12}=\frac{60+31}{26.12}=\frac{91}{26.12}=\frac{13.7}{13.2.12}=\frac{7}{24}\)

Bài 2 :

a)\(28.157-28.267+28.10\)

\(=28\left(157-267+10\right)\)

\(=28.-100\)

\(=-2800\)

b)\(\left(-5\right).4.\left(-2\right).23.\left(-25\right)\)

\(=\left[4.\left(-25\right)\right].\left[\left(-5\right).2\right].23\)

\(=\left(-100\right).\left(-10\right).23\)

\(=23000\)

2)

28 . 157  -  28 .267 + 28.10 

=28.( 157 - 267 + 10 )

= 28 . -100

= -2800

3)

[(-2).(-5)]. 4 .-25.23

= 10 . -100 .23

=-23000

còn câu 1 mik suy nghĩ đã

a: \(-472+\left(235-28\right)-\left(35-350\right)\)

\(=-472+235-28-35+350\)

\(=\left(-472-28\right)+\left(235-35\right)+350\)

=-500+350+200

=50

b: \(91\cdot172+91\cdot13-91\cdot85\)

\(=91\cdot\left(172+13-85\right)\)

\(=91\cdot100=9100\)

c: \(798-298:\left[19-2\left(5^2-22\right)^2\right]\cdot1^{2023}\)

\(=798-298:\left[19-2\left(25-22\right)^2\right]\)

\(=798-298:\left[19-2\cdot3^2\right]\)

\(=798-298:\left(19-18\right)\)

=798-298

=500

E cảm ơn ạ 👍