Đăng 1 bài 1 thổi bn

\(\frac{5}{9}\times\frac{12}{7}=\frac{5\times12}{9\times7}=\frac{5\times4\times3}{3\times3\times7}=\frac{20}{21}\)

\(\frac{6}{5}:\frac{8}{3}=\frac{6}{5}\times\frac{8}{3}=\frac{2\times3\times8}{5\times3}=\frac{16}{5}\)

\(\frac{9}{20}\times\frac{5}{12}=\frac{3\times3\times5}{4\times5\times4\times3}=\frac{3}{16}\)

\(\frac{15}{16}:\frac{25}{24}=\frac{15}{16}\times\frac{24}{25}=\frac{3\times5\times4\times2\times3}{4\times2\times2\times5\times5}=\frac{9}{10}\)

\(14\times\frac{5}{21}=\frac{2\times7\times5}{3\times7}=\frac{10}{3}\)

\(10:\frac{5}{3}=10\times\frac{3}{5}=\frac{2\times5\times3}{5}=6\)

\(\frac{5}{3}:10=\frac{5}{3}\times\frac{1}{10}=\frac{5}{3\times2\times5}=\frac{1}{6}\)

tương tự bài 2

bài 3 tính diện tích là chiều dài nhân chiều rộng ra rồi chia cho 5

(-3/4+2/3);5/11+(-1/4+1/3):5/11

=-1/12:5/11+1/12:5/11

=(-1/12:+1/12):5/11

=0:5/11=0

a=-31 phần 60

b=13 phần 4

c=-2

em mới có lớp 2

\(\frac{125}{100}:\frac{15}{20}\times\left(\frac{1}{4}-\frac{5}{6}\right):\frac{14}{3}\)

=\(\frac{125}{100}\times\frac{20}{5}\times\left(\frac{1}{4}-\frac{5}{6}\right):\frac{3}{14}\)

=\(\frac{5}{4}\times\frac{4}{3}\times\left(\frac{6}{24}-\frac{20}{24}\right)\times\frac{3}{14}\)

=\(\frac{5}{4}\times\frac{4}{3}\times\frac{-7}{12}\times\frac{3}{14}\)

=\(\frac{5\times4\times\left(-7\right)\times3}{4\times3\times12\times14}\)

=\(\frac{-420}{2016}\)

=\(\frac{-5}{24}\)

Chúc bạn học tốt

tích đúng giúp mình

12/17 chia 4 = 3/17

12 chia 6/13=26

9 chia 3/5*4/15=4

\(\frac{12}{17}:4=\frac{12}{17}.\frac{1}{4}=\frac{3}{17}.\frac{1}{1}=\frac{3}{17}\)

\(12:\frac{6}{13}=12.\frac{13}{6}=2.\frac{13}{1}=26\)

\(9:\frac{3}{5}.\frac{4}{15}=9.\frac{5}{3}.\frac{4}{15}=3.\frac{5}{1}.\frac{4}{15}=\frac{15}{1}.\frac{4}{15}=\frac{1}{1}.\frac{4}{1}=4\)

Hok tốt!!!

chịu thôi

:v vãi

vì đây là bài toán sai

1/5+7/13×(-1/2+5/8)÷14/24

1/5+7/13×1/8÷14/24

1/5+7/13×24/14

1/5+12/13

13/63+60/63

73/63

           Bài làm :

Ta có :

\(\frac{7}{11}\div\left(\frac{2}{10}+\frac{5}{11}\right)+\frac{1}{30}=\frac{7}{11}\div\frac{36}{55}+\frac{1}{30}=\frac{35}{36}+\frac{1}{30}=\frac{181}{180}\)

Bài làm :

\(\frac{7}{11}:\left(\frac{2}{10}+\frac{5}{11}\right)+\frac{1}{30}\)

\(=\frac{7}{11}:\frac{36}{55}+\frac{1}{30}\)

\(=\frac{35}{36}+\frac{1}{30}\)

\(=\frac{181}{180}\)

Học tốt

1,

\(\frac{25}{12}+\left(\frac{-4}{12}\right)=\frac{7}{4}\)

\(\frac{-10}{8}+\frac{15}{4}=\frac{5}{2}\)

\(\frac{3}{8}+\frac{-14}{6}=\frac{-47}{24}\)

\(\frac{350}{150}+\left(\frac{-200}{360}\right)=\frac{16}{9}\)

\([\frac{5}{8}+\left(\frac{-3}{4}\right)]+\frac{15}{6}=\frac{-1}{8}+\frac{15}{6}=\frac{19}{8}\)

\(\frac{7}{3}+[\left(\frac{-5}{6}\right)+\left(\frac{-2}{3}\right)]=\frac{7}{3}+\left(\frac{-3}{2}\right)=\frac{5}{6}\)

4,

\(\frac{X+1}{5}=\frac{3}{7}\)

\(\Rightarrow\left(X-1\right).7=3.5\)

\(\Rightarrow7X-7=15\)

\(\Rightarrow7X=22\)

\(\Rightarrow X=\frac{22}{7}\)

\(\frac{X-3}{4}=\frac{1}{2}\)

\(\Rightarrow\left(X-3\right)2=1.4\)

\(\Rightarrow2X-6=4\)

\(\Rightarrow2X=10\)

\(\Rightarrow X=5\)

Tôi ko bt