Trl : 

3³ .1⁸- 3³.15

= 27.1 - 27.15

= 27.( 1 - 15 )

= 27.(-14)

= -378

Hok tốt nhá :>

  3³.1⁸-3³.15

=27.1-27.15

=27.(1-15)

=27.(-14)

=-378

3 giờ 15 phút > 3,15 giờ

Các phần dưới tương tự nhé

ai k mình mình k lại

`-3/3*15/13-3/7*11/13-3/7`

`-1*15/13-3/7*11/13-3/7`

`=-3/7:3/7*15/13-3/7*11/13-3/7`

`=-3/7*35/13-3/7*11/13-3/7`

`=-(3/7*35/13+3/7*11/13+3/7)`

`=-3/7(35/13+11/13+1)`

`=-3/7*59/13`

`=-177/91`

$-3/3\ast 15/13-3/7\ast 11/13-3/7$

$-1\ast 15/13-3/7\ast 11/13-3/7$

$=-3/7:3/7\ast 15/13-3/7\ast 11/13-3/7$

$=-3/7\ast 35/13-3/7\ast 11/13-3/7$

$=-(3/7\ast 35/13+3/7\ast 11/13+3/7)$

$=-3/7(35/13+11/13+1)$

$=-3/7\ast 59/13$

$=-177/91$

A=\(\dfrac{3}{4}.\dfrac{8}{9}.....\dfrac{9999}{10000}\)

A=\(\dfrac{1.3}{2.2}.\dfrac{2.4}{3.3}.....\dfrac{99.101}{100.100}\)

A=\(\dfrac{1.2.3.....99}{2.3.4.....100}.\dfrac{3.4.....101}{2.3.4.....100}\)

A=\(\dfrac{1}{100}.\dfrac{101}{2}\)

A=\(\dfrac{101}{200}\)

\(A=\dfrac{1.3}{2.2}.\dfrac{2.4}{3.3}.\dfrac{3.5}{4.4}.....\dfrac{99.101}{100.100}\\ =\dfrac{1}{2}.\dfrac{101}{100}=\dfrac{101}{200}\)

\(B=\left(1-\dfrac{1}{4}\right)\left(1-\dfrac{1}{9}\right)...\left(1-\dfrac{1}{10000}\right)\\ =\dfrac{3}{4}.\dfrac{8}{9}...\dfrac{9999}{10000}\)

(làm như câu a)

-4 . (-3 . 15) . 2,5 - 1,25 . (-4,1) . 8 + 0,2

= -4 . (-45) . 2,5 - (-5,125) . 8 + 0,2

= 180 . 2,5 - (-41) + 0,2

= 450 + 41 + 0,2

= 491,2

sai thì thôi nha!