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.

=25-3=22

\(=5^2 - 3=25-3=22\)

\(\dfrac{2}{67}-\left(\dfrac{3}{7}+\dfrac{2}{67}\right)\\ =\dfrac{2}{67}-\dfrac{215}{469}\\ =\dfrac{-3}{7}\)

\(\dfrac{3}{4}.\dfrac{5}{2}+\dfrac{5}{4}.\dfrac{5}{2}\\ =\left(\dfrac{3}{4}+\dfrac{5}{4}\right).\dfrac{5}{2}\\ =2.\dfrac{5}{2}\\ =\dfrac{5}{1}\)

a, \(=\frac{27}{45}+\frac{-25}{45}\)

\(=\frac{2}{45}\)

b, \(=\frac{4}{13}+\frac{-4}{13}\)

\(=0\)

c, \(=\frac{1}{5}+\frac{-4}{5}\)

\(=\frac{-3}{5}\)

Nhớ tích hộ mình nhaaaaaaa!!!!!

5⁶⁹ : 5^{67 -} 3^40: 3³⁹ = 5² - 3 = 25 - 3 = 22

5^59 : 5^67 - 3^40 : 3^39 

= ( 5^59 : 5^57 ) - ( 3^40 : 3^39 )

= 5^2 - 3^1 

= 25 - 1 

= 24

a, A = ( 1/3 + 12/67 + 13/41 ) - ( 79/67 - 28/41 )

A = (\(\frac13\) + \(\frac{12}{67}\) + \(\frac{13}{41}\)) - (\(\frac{79}{67}\) - \(\frac{28}{41}\))

A = \(\frac13\) + \(\frac{12}{67}\) + \(\frac{13}{41}\) - \(\frac{79}{67}\) + \(\frac{28}{41}\)

A = - (\(\frac{79}{67}-\frac{12}{67}\)) + (\(\frac{13}{41}\) + \(\frac{28}{41}\))

A = - 1 + 1 + \(\frac13\)

A = 0 + \(\frac13\)

A = \(\frac13\)

b, B = 3/4×7 + 3/7×10 + 3/10×13 + ......+ 3/73×76

B = \(\frac{3}{4\times7}\) + \(\frac{3}{7\times10}\) + \(\frac{3}{10\times13}\) + ... + \(\frac{3}{73\times76}\)

B = \(\frac14-\frac17\) + \(\frac17-\frac{1}{10}\) + ... + \(\frac{1}{73}-\frac{1}{76}\)

B = \(\frac14\) - \(\frac{1}{76}\)

B = \(\frac{19}{76}-\) \(\frac{1}{76}\)

B = \(\frac{18}{76}\)

B = \(\frac{9}{38}\)

b:\(1+2+3+...+n=\dfrac{n\left(n+1\right)}{2}\)

c: \(1+3+5+...+37\)

Số số hạng là:

(37-1):2+1=19(số)

Tổng là: \(\dfrac{38\cdot19}{2}=19\cdot19=361\)

Bài 2: 

a: =>x-35=-23

=>x=12

b: =>|x-8|=13

=>x-8=13 hoặc x-8=-13

=>x=21 hoặc x=-5

Bài 1: 

a: =42-98-42+12-12=-98

b: =10x4x3x(-25)=40x(-25)x3=-1000x3=-3000