cách 1: 9/5:17/15 + 8/5:17/15=27/17+24/17=3

cách 2 :9/5:17/15+8/5:17/15=17/15 x15/17+8/5 x15/17=15/17 x (9/5+8/5)=15/17 x 17/5 = 3

\(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}\)

\(=\frac{17}{15}:\left(\frac{9}{5}+\frac{8}{5}\right)\)

\(=\frac{17}{15}:3\)

\(=\frac{17}{45}\)

\(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{5}=\frac{9}{5}.\frac{15}{17}+\frac{8}{5}.\frac{15}{17}=\frac{15}{17}\left(\frac{9}{5}+\frac{8}{5}\right)=\frac{15}{17}.\frac{17}{5}=3\)

   9/5 : 17/15 + 8/5 : 17/15

= ( 9/5 + 8/5 ) x 15/17

= 17/5 x 15/17

= 3

9/8 : 27/16 =2/3

C1: 9/5:17/15 + 8/5 : 17/15

= 27/15 + 24/15

=3

C2: 9/5 : 17/15 + 8/5 : 17/15

= ( 9/5 + 8/5 ) : 17/15

= 17/5 : 17/15

= 3

( 9/5 +  8/5 )  : 17 /15

= 17/15 : 17/15

=225/85=3

\(=\frac{\left(\frac{9}{5}+\frac{8}{5}\right)}{\frac{17}{15}}=\frac{\left(\frac{17}{5}\right)}{\left(\frac{17}{15}\right)}=\frac{255}{85}\)

\(=\frac{135}{85}+\frac{120}{85}=\frac{255}{85}\)

C1:(9/5+8/5):17/15=17/5:17/15=3(nhớ bình chọn nha)

C2;27/17+24/17=3(nhớ bình chọn nha)

cách 1: \(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}=\frac{9}{5}.\frac{15}{17}+\frac{8}{5}.\frac{15}{17}=\frac{15}{17}.\left(\frac{9}{5}+\frac{8}{5}\right)=\frac{15}{17}.\frac{17}{5}=3\)

cách 2: \(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}=\frac{9}{5}.\frac{15}{17}+\frac{8}{5}.\frac{15}{17}=3.\frac{3}{17}+8.\frac{3}{17}=\frac{27}{17}+\frac{24}{17}=\frac{51}{17}=3\)

có ai học ở trường thanh xuân nam hà nội ko

= 17/15 : ( 9/5 + 8,5 )

=  17/15 :17/5

= 1/3

\(\dfrac{9}{5}:\dfrac{17}{15}+\dfrac{8}{5}:\dfrac{17}{15}=\dfrac{9}{5}\times\dfrac{15}{17}+\dfrac{8}{5}\times\dfrac{15}{17}=\dfrac{15}{17}\times\left(\dfrac{9}{5}+\dfrac{8}{5}\right)=\dfrac{15}{17}\times\dfrac{17}{5}=\dfrac{255}{85}=3\)

9/5 : 17/15 + 8/5 : 17/15= 17/15 : ( 9/5 + 8,5 )

                                      =  17/15 :    17/5

                                      =      1/3

 A) cách 1\(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}\)

\(=\frac{9}{5}\cdot\frac{15}{17}+\frac{8}{5}\cdot\frac{15}{17}\)

\(=\frac{135}{85}+\frac{120}{85}\)

\(=\frac{255}{85}\)

\(=3\)

Cách 2\(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}\)

\(=\frac{9}{5}\cdot\frac{15}{17}+\frac{8}{5}\cdot\frac{15}{17}\)

\(=\frac{15}{17}\cdot\left(\frac{9}{5}+\frac{8}{5}\right)\)

=\(\frac{15}{17}\cdot\frac{17}{5}\)

\(=\frac{15\cdot17}{17\cdot5}\)

\(=\frac{5\cdot3\cdot17}{17\cdot5}\)

\(=3\)

B) Cách 1 :

0,9 : 0,25 + 1,05 : 0,25

= 3,6 + 4,2

=7,8

Cách  2:

0,9 : 0,25 + 1,05 : 0,25

\(=0,9:\frac{1}{4}+1,05:\frac{1}{4}\)

\(=0,9\cdot4+1,05\cdot4\)

\(=4\cdot\left(0,9+1,05\right)\)

\(=4\cdot1,95\)

=\(7,8\)

a: \(=\dfrac{3}{5}:\dfrac{7}{5}=\dfrac{3}{5}\cdot\dfrac{5}{7}=\dfrac{3}{7}\)

b: \(=\dfrac{9}{17}\left(\dfrac{8}{5}-\dfrac{3}{5}\right)+\dfrac{8}{17}\)

=9/17+8/17=1

c: =>x-3/10=7/15*1/5=7/75

=>x=7/75+3/10=59/150

= 51/17

sao lai ra 51/17 vay ban

      \(\frac{9}{5}:\frac{17}{15}+\frac{8}{5}:\frac{17}{15}\)

\(=\frac{17}{15}:\left(\frac{9+8}{5}\right)\)

\(=\frac{17}{15}:\frac{17}{5}\)

\(=\frac{17}{15}X\frac{5}{17}\)

\(=\frac{1}{3}\)

Chúc bn học tốt

Tk cho mình nhé