Giải 

a) 5⁶⁹ : 5⁶⁷ – 3⁴⁰ : 3³⁹ = 5² – 3¹ = 25 – 3 = 22

b) 155 – [ 2 . ( 30 + 5 – 26 ) . ( 24 : 3 )]

= 155 – [ 2 . 9 . 8 ] = 155 – 144 = 11

c) 37 . 143 + 37 . 57 + 1300

= (37 . 143 + 37.57) + 1300

= 37.(143+ 57) + 1300

= 37. 200 + 1300

= 7400 + 1300

8700.

a) 569 : 567 – 340 : 339 = 52 – 31 = 25 – 3 = 22

b) 155 – [ 2 . ( 30 + 5 – 26 ) . (24 : 2 )]

= 155 – [ 2 . 9 . 8 ] = 155 – 144 = 11

c) 8700.

a, (19-51)-(x-23)=-6

19-51-x+23=-6

-32-x+23=-6

-32-x=-6-23

-32-x=-29

x=-32+(-29)

x=-61

-5x-10(-7)=55

-5x+70=55

-5x=55-70

-5x=-15

x=-15:(-5)

x=3

c, -7-2x=-37-(-26)

-7-2x=-37+26

-7-2x=11

-2x=11+7

-2x=18

x=-9

d, /2x-1/=/-5/

2x-1=5

2x=5+1

2x=6

x=6:2

x=3

e, 2-/x+5/=7

2-x+5=7

2-x=7-5

2-x=2

x=2-2

x=0

h, (x+8)²=25

(x+8)²=5²

x+8=5

x=5-8

x=-3

f, (x+3)³:3-1=-10

(x+3)³:3=-10+1

(x+3)³:3=-9

(x+3)³:3=3³

x+3:3=3

x+3=9

x=9-3

x=6

k mk nhe

minh h rui day thanhs mha bn ma bn kb vs minh va giups minh giai toan ko

a) 3 . 5² + 15 . 2² - 26 : 2

= 3 . 25 + 15 . 4 - 26 : 2

= 75 + 60 - 13

= 122

b) (5¹⁹ : 5¹⁷ + 3) : 7

= (5² + 3) : 7

= (25 + 3) : 7

= 28 : 7

= 4

7: =6-7+4-3=0

8: =8x5-9x4+4x6=40-36+24=28

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

a) 2\(^3\).15 -[115-(12-5)\(^2\)]

=   8.15-[115-(7)\(^2\)]

=   120-[115-49]

 =   120-66

=     54

c)4.5\(^2\)- 81:3\(^2\)+3\(^2\).22-3\(^3\).19

=4.25-81:9+9.22-27.19

=100-9+198-513

=91+198-513

=289-513

=(-224)

Câu b sai đề nhé bn

BẠN ƠI , MIH XIN LỖI NHA , DẤU BẰNG LÀ DẤU CỘNG ĐÓ

\(=\frac{7.6^{11}.2^{19}.3^5-2^{19}.6^{15}}{3^{21}.2^{28}-3^{17}.2^{28}}=\frac{2^{19}.6^{11}.\left(7.3^5-6^4\right)}{3^{17}.2^{28}.\left(3^4-1\right)}=\frac{2^{30}.3^{11}.3^4.\left(7.3-2^4\right)}{3^{17}.2^{28}.\left(3^4-1\right)}=\frac{2^2.13}{3^2.80}=\frac{13}{9.20}=\frac{13}{180}\)

phải ra là 1/36 bạn làm nhầm bước 2^2.5/3^2.80=1/36

Bài 1: 74+(-93)+2014+(-7)+26

=(74+26)+[-93+(-7)]+2014

=100+(-100)+2014=2014

Bài 2:

15+2|x|=97

2|x|=97-15=82

|x|=82:2=41

Suy ra: x=41; x=-41

Bài 3:

Ta có: A=3+3^2+3^3+3^4+3^5+..+3^19+3^20+3^21

=(3+3^2+3^3)+(3^4+3^5+3^6)+...+(3^19+3^20+3^21)

=3.(1+3+3^2)+3^3.(1+3+3^2)+...+3^18.(1+3+3^2)

=3.13+3^3.13+...+3^18.13

=13.(1+3^3+..+3^18) (chia hết cho 13)

Vậy A chia hết cho 13

\(a)3-\left(17-x\right)=-24+12\)

\(\Leftrightarrow3-17+x=-12\)
\(\Leftrightarrow-14+x=-12\)

\(\Leftrightarrow x=-12+14=2\)

a)  3 - (17 - x) = -24 + 12

=> 3 - 17 + x = -12

=> -14 + x = -12

=> x = -12 + 14

=> x = 2

b) -5 + (16 - x) = 2².3 - 5²

=> -5 + 16 - x = 12 - 25

=> 11 - x = -13

=> x = 11 + 13

=> x = 24

c) -26 - (x - 7) = 3⁴ - 9²

=> -26 - x + 7 = 81 - 81

=> -19 - x = 0

=> x = -19 - 0

=> x = -19

d) -36 - (4 - x) = 37 + (-5)

=> -36 -  4 + x = 32

=> -40 + x = 32

=> x = 32 + 40

=> x = 72