`(2/3xx4/5)xx5/6`

`=2/3xx4/5xx5/6`

`=2/3xx4/6`

`=2/3xx2/3`

`=1`

__

`(4/5+5/4)xx3/4`

`=(16/20+25/20)xx3/4`

`=41/20xx3/4`

`=123/80`

__

`27/12+17/6-25/36-15/6`

`=(27/12-25/36)+(17/6-15/6)`

`=(81/36-25/36)+2/6`

`=56/36+2/6`

`=56/36+12/36`

`=68/36`

`=17/9`

TL: 

8/15 x 5/6 = 40/90 = 4/9 

41/20 x 3/4 = 123/80 

(11/23 + 9/23) + (18/23 + 2/23) = 20/23 + 20/23 = 40/43 

HT

\(\left(\frac{2}{3}\times\frac{4}{5}\right)\times\frac{5}{6}\) = \(\frac{2}{3}\times\frac{4}{5}\times\frac{5}{6}\)=\(\frac{2\times4\times5}{3\times5\times6}\)=\(\frac{2\times4\times5}{3\times5\times2\times3}\)=\(\frac{4}{9}\)

\(\frac{11}{23}+\frac{2}{23}+\frac{9}{23}+\frac{18}{23}\)=\(\frac{\left(11+9\right)+\left(18+2\right)}{23}\)=\(\frac{20+20}{23}\)=\(\frac{40}{23}\)

\(\frac{27}{12}+\frac{17}{6}-\frac{25}{36}-\frac{15}{6}\)=\(\left(\frac{27}{12}-\frac{25}{36}\right)+\left(\frac{17}{6}-\frac{15}{6}\right)\)=\(\frac{14}{9}+\frac{2}{6}\)=\(\frac{17}{9}\)

/HT\

Nhập các bạn toàn bắt tớ làm à ngu gò mà làm

37 x 18 - 9 x 14 + 100

=37*2*9-9*14+100

=74*9-9*14+100

=9*(74-14)+100

=9*60+100

=540+100

=640

15 x 2 + 15 x 3 + 15 x 5

=15*(2+3+5)

=15*10

=150

52 + 37 + 48 + 63

=(52+48)+(37+63)

=100+100

=200

37 x 18 - 9 x 14 + 100 = 37 x 2 x 9 - 9 x 14 + 100

= 74 x 9 - 9 x 14 + 100

= (74 - 14) x 9 +100

= 60 x 9 + 100

= 540 + 100

= 550

15 x 2 + 15 x 3 + 15 x 5 = 15 x ( 2 + 3 +5 )

= 15 x 10

= 150

52 + 37 + 48 + 63 = (52 + 48) + (37 + 63)

= 100 + 100

= 200

Duyệt!!!

37 x 18 - 9 x 14 + 100 = 37 x 2 x 9 - 9 x 14 + 100

= 74 x 9 - 9 x 14 + 100

= (74 - 14) x 9 +100

= 60 x 9 + 100

= 540 + 100

= 550

15 x 2 + 15 x 3 + 15 x 5 = 15 x ( 2 + 3 +5 )

= 15 x 10

= 150

52 + 37 + 48 + 63 = (52 + 48) + (37 + 63)

= 100 + 100

= 200

 a,  \(\dfrac{5\times11\times15\times18}{6\times15\times22\times10}\)

= \(\dfrac{5\times11\times15\times6\times3}{6\times15\times11\times2\times2\times5}\)

= \(\dfrac{5\times11\times15\times6}{5\times11\times15\times6}\) \(\times\) \(\dfrac{3}{2\times2}\)

= 1 \(\times\) \(\dfrac{3}{4}\)

= \(\dfrac{3}{4}\)

b, \(\dfrac{7}{12}\) \(\times\) \(\dfrac{3}{5}\) + \(\dfrac{3}{5}\) \(\times\) \(\dfrac{5}{12}\)

= \(\dfrac{3}{5}\) \(\times\) ( \(\dfrac{7}{12}+\dfrac{5}{12}\))

= \(\dfrac{3}{5}\) \(\times\) \(\dfrac{12}{12}\)

= \(\dfrac{3}{5}\) \(\times\) 1 

= \(\dfrac{3}{5}\)

 36-4x9 = 36 - 36 = 0 Vì số nào nhân với 0 thì cũng bằng 0 nên phép tính đó bằng 0

a: 3km75m=3,075m

\(\dfrac{1}{4}m^2=25dm^2\)

3h15'=195p

b: 26320:35=752

c: =3/5(5/12+7/12)

=3/5

a, \(3km75m=3075m\)

\(\dfrac{1}{4}m^2=25\text{d}m^2\)

`3` giờ `15` phút = `195` phút

b,

`->26320 : 35=752.`

c, \(\dfrac{9}{15}\times\dfrac{5}{12}+\dfrac{9}{15}\times\dfrac{7}{12}=\dfrac{9}{15}\times\left(\dfrac{5}{12}+\dfrac{7}{12}\right)=\dfrac{9}{15}\times1=\dfrac{9}{15}\)

`@mt`

\(\frac{5x8x24x27}{8x15x9x7}=\frac{5x8x24x9x3}{8x5x3x9x7}=\frac{24}{7}\)

Chúc bạn học tốt.

😁😁😁

Ta tính thuận tiện bằng cách phân tích các thừa số để bỏ thừa số chung:

\(\frac{5\text{x}8\text{x}24\text{x}27}{8\text{x}15\text{x}9\text{x}7}=\frac{5\text{x}8\text{x}3\text{x}8\text{x}3\text{x}3\text{x}3}{8\text{x}3\text{x}5\text{x}3\text{x}3\text{x}7}\)

\(=\frac{8\text{x}3}{7}\)

\(=\frac{24}{7}\)

\(\dfrac{3}{12}\)x\(\dfrac{15}{6}\)x\(\dfrac{8}{5}\)

=> \(\dfrac{5}{8}\)x\(\dfrac{8}{5}\)

=>1

\(\dfrac{3}{12}\times\dfrac{15}{6}\times\dfrac{8}{5}=1\)

=1