Câu 10:

\(a,y\times7+y\times3=70\\ \Rightarrow y\times\left(7+3\right)=70\\ \Rightarrow y\times10=70\\ \Rightarrow y=7\\ b,18:y+12:y=3\\ \Rightarrow\left(18+12\right):y=3\\ \Rightarrow30:y=3\\ \Rightarrow y=10\)

câu 11:

\(a,9\times365+2\times365-365=\left(9+2-1\right)\times365=10\times365=3650\\ b,108:9-18:9=\left(108-18\right):9=90:9=10\\ c,43\times95+4\times43+43=43\times\left(95+4+1\right)=43\times100=4300\)

a: 9/11=1-2/11

11/13=1-2/13

mà -2/11<-2/13

nên 9/11<11/13

b: 19/15=1+4/15

15/11=1+4/11

mà 4/15<4/11

nên 19/15<15/11

14/15 + 2/11 + 1/15 + 4/11 + 10/20 

=(14/15+1/15)+(2/11+4/11)+10/20

=1+6/11+10/20

=17/11+10/20

=45/22

Cái 17/11 à

1+6/11=17/11

bn ko hiểu chỗ nào bảo mik

\(\frac{14}{15}+\frac{2}{11}+\frac{1}{15}+\frac{4}{11}+\frac{10}{20}\)

\(=\left(\frac{14}{15}+\frac{1}{15}\right)+\left(\frac{2}{11}+\frac{4}{11}\right)+\frac{10}{20}\)

\(=1+\frac{6}{11}+\frac{10}{20}\)

\(=\frac{17}{11}+\frac{10}{20}\)

\(=\frac{45}{22}\)

14/15+3/11+1/15+3/11=10/22

=[14/15+1/15]+[3/11+3/11]

=[14/15+1/15]+[3/11*2]

= 1+6/11

=17/11

sai bet!!

các bn nào đang online giải hộ mk vs

a)\(\frac{21}{11}.\frac{22}{17}.\frac{68}{63}=\frac{21.22.68}{11.17.63}=\frac{21.2.11.4.17}{11.17.3.21}=\frac{\left(11.17.21\right)2.4}{\left(11.17.21\right).3}=\frac{2.4}{3}=\frac{8}{3}\)

b)\(\frac{5}{14}.\frac{7}{13}.\frac{26}{25}=\frac{5.7.26}{14.13.25}=\frac{5.7.13.2}{7.2.13.5.5}=\frac{\left(5.7.13\right).2}{\left(5.7.13\right).2.5}=\frac{2}{2.5}=\frac{1}{5}\)

a.     2 x 134 x 5 = (2 x 5) x 134

                   = 10 x 134

                   = 1340

b. 43 x 95 + 5 x 43

= 43 x (95 + 5)

= 43 x 100 = 4300

\(\frac{5}{11}.\frac{7}{25}+\frac{15}{11}.\frac{1}{5}\)

\(=\frac{5}{11}.\frac{7}{25}+\frac{5}{11}.3.\frac{1}{5}\)

\(=\frac{5}{11}.\frac{7}{25}+\frac{5}{11}.\frac{3}{5}\)

\(=\frac{5}{11}\left(\frac{7}{25}+\frac{3}{5}\right)\)

\(=\frac{5}{11}\left(\frac{7}{25}+\frac{15}{25}\right)\)

\(=\frac{5}{11}.\frac{22}{25}=\frac{2}{5}\)

2/5 nhé

   5/11x7/25+15/11x1/5

=5/11x(7/25+1/5)

=5/11x12/25

=12/55

Chúc bn hok tốt