cách 1 \(\left(\dfrac{6}{11}+\dfrac{7}{5}\right)\cdot\dfrac{3}{7}\\ =\dfrac{107}{55}\cdot\dfrac{3}{7}=\dfrac{321}{385}\)cách 2 \(\left(\dfrac{6}{11}+\dfrac{7}{5}\right)\cdot\dfrac{3}{7}\\ =\dfrac{6}{11}\cdot\dfrac{3}{7}+\dfrac{7}{5}\cdot\dfrac{3}{7}\\ =\dfrac{18}{77}+\dfrac{3}{5}=\dfrac{321}{385}\)

cách 1 \(\left(\dfrac{6}{7}-\dfrac{1}{2}\right)\cdot\dfrac{2}{5}\\ =\dfrac{5}{14}\cdot\dfrac{2}{5}=\dfrac{1}{7}\) cách 2 \(\left(\dfrac{6}{7}-\dfrac{1}{2}\right)\cdot\dfrac{2}{5}\\ =\dfrac{6}{7}\cdot\dfrac{2}{5}-\dfrac{1}{2}\cdot\dfrac{2}{5}\\ =\dfrac{12}{35}-\dfrac{1}{5}=\dfrac{1}{7}\)

[ \(\dfrac{6}{11}\)  + \(\dfrac{7}{5}\)] x \(\dfrac{3}{7}\)

= [ \(\dfrac{30}{55}\) + \(\dfrac{77}{55}\)] x \(\dfrac{3}{7}\)

= \(\dfrac{107}{55}\)x \(\dfrac{3}{7}\)

= \(\dfrac{321}{385}\)

[ \(\dfrac{6}{11}\) + \(\dfrac{7}{5}\)] x \(\dfrac{3}{7}\)

= \(\dfrac{6}{11}\) x \(\dfrac{3}{7}\) + \(\dfrac{7}{5}\) x \(\dfrac{3}{7}\)

= \(\dfrac{18}{77}\)   +  \(\dfrac{3}{5}\)

= \(\dfrac{90}{385}\) + \(\dfrac{231}{385}\)

= \(\dfrac{321}{385}\)

 [ \(\dfrac{6}{7}\) - \(\dfrac{1}{2}\)] x \(\dfrac{2}{5}\)

= [ \(\dfrac{12}{14}\) - \(\dfrac{7}{14}\)] x \(\dfrac{2}{5}\)

= \(\dfrac{5}{14}\)  x \(\dfrac{2}{5}\)

= \(\dfrac{1}{7}\)

[ \(\dfrac{6}{7}\) - \(\dfrac{1}{2}\)] x \(\dfrac{2}{5}\)

= \(\dfrac{6}{7}\) x \(\dfrac{2}{5}\) - \(\dfrac{1}{2}\) x \(\dfrac{2}{5}\)

= \(\dfrac{12}{35}\) - \(\dfrac{1}{5}\)

= \(\dfrac{12}{35}\) - \(\dfrac{7}{35}\)

= \(\dfrac{5}{35}\)

= \(\dfrac{1}{7}\)

Số bạn nữ khối 4 là : ( 135 - 15) : 2 = 60 ( bạn)

Số bạn nam khối 4 là : 135 - 60 = 75 (bạn)

Đáp số:.....

giúp tớ với, tớ đang cần gấp

t

X×62+X×48=4200

\(x\times\left(62+48\right)=4200\)

\(x\times110=4200\)

\(x=4200:110\)

\(x=\dfrac{420}{11}\)

X x 62 + X x 48= 4200

X x(62 + 48)= 4200

X x 110= 4200

X = 4200 : 110

X = 4200/ 110= 420/ 11

`8-15/6`

`=8-5/2`

`=16/2-5/2`

`=11/2`

`52/17-3`

`=52/17-51/17`

`=1/17`

$a)8-15/6$

$=8-5/2$

$=16/2-5/2$

$=11/2$

$b)52/17-3$

$=52/17-51/17$

$=1/17$

help me

a = 48/6 - 15/6 = 33/6 = 11/3

b = 52/17 - 51/17 = 1/17 

`1/3-2/15+14/15`

`=5/15-2/15+14/15`

`=17/15`

`3/5+4-6/7`

`=21/35+140/35-30/35`

`=131/35`

giúp mình với ạ, thanks!

`6:2xx(1+2)`

`= 6:2 xx 3`

`=3 x 3`

`=9`

ấn máy tính là 9 nên xóa

chắc là chia trước

`1/5+x=5/6`

`=> x=5/6-1/5`

`=> x=25/30-6/30`

`=> x=19/30`

`1/5 + x=5/6`

`=>x=5/6-1/5`

`=>x=25/30 - 6/30`

`=>x= 19/30`