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13 tháng 4 2020

hihi

13 tháng 4 2020

\(\frac{14}{x}=\frac{4}{6}\)

<=>\(x=\frac{14.6}{4}\)

<=>\(x=21\)

31 tháng 5 2018

\(\frac{14}{6}+\frac{1}{3}+\frac{14}{14}+\frac{14}{9}+\frac{7}{15}+\frac{6}{4}\)

\(=\frac{14}{6}+\frac{1}{3}+\frac{14}{9}+\frac{7}{15}+\frac{14}{14}+\frac{6}{4}\)

\(=\frac{42+6+28}{18}+\frac{7}{15}+\frac{2}{2}+\frac{3}{2}\)

\(=\frac{76}{18}+\frac{7}{15}+\frac{5}{2}\)

\(=\frac{76}{18}+\frac{5}{2}+\frac{7}{15}\)

\(=\frac{76+45}{18}+\frac{7}{15}\)

\(=\frac{121}{18}+\frac{7}{15}\)

\(=\frac{605+42}{90}\)

\(=\frac{647}{90}\)

31 tháng 5 2018

\(\frac{14}{6}+\frac{1}{3}+\frac{14}{14}+\frac{14}{9}+\frac{7}{15}+\frac{6}{4}\)

\(=(\frac{7}{3}+\frac{1}{3})+1+(\frac{14}{9}+\frac{7}{15})+\frac{3}{2}\)

\(=\frac{8}{3}+1+\frac{91}{45}+\frac{3}{2}\)

\(=2+\frac{2}{3}+1+2+\frac{1}{45}+1+\frac{1}{2}\)

\(=\left(\frac{2}{3}+\frac{1}{45}+\frac{1}{2}\right)+\left(2+1+2+1\right)\)

\(=1+\frac{17}{90}+6\)

\(=7+\frac{17}{90}\)

\(=7\frac{17}{90}\)

25 tháng 2 2018

a, \(\frac{6}{7}.\frac{16}{15}.\frac{7}{6}.\frac{21}{32}=\frac{6}{7}.\frac{7}{6}.\frac{16}{15}.\frac{21}{32}\)=\(1.\frac{16}{15}.\frac{21}{32}=\frac{7}{5.2}=\frac{7}{10}\)

Phần b T2

c,\(\frac{7}{4}.\frac{11}{21}+\frac{11}{21}.\frac{5}{4}=\frac{11}{21}.\left(\frac{7}{4}+\frac{5}{4}\right)\)=\(\frac{11}{21}.3=\frac{11}{7}\)

25 tháng 2 2018

cảm ơn bạn nha

HQ
Hà Quang Minh
Giáo viên
2 tháng 11 2023

a) $\frac{4}{{25}}:\frac{4}{3} = \frac{4}{{25}} \times \frac{3}{4} = \frac{3}{{25}}$ 

b) $\frac{3}{{14}}:\frac{6}{7} = \frac{3}{{14}} \times \frac{7}{6} = \frac{{3 \times 7}}{{14 \times 6}} = \frac{{3 \times 7}}{{7 \times 2 \times 3 \times 2}} = \frac{1}{4}$

c) $\frac{{12}}{{15}}:2 = \frac{{12}}{{15}} \times \frac{1}{2} = \frac{{12 \times 1}}{{15 \times 2}} = \frac{{6 \times 2 \times 1}}{{15 \times 2}} = \frac{6}{{15}}$           

d) $\frac{{21}}{8}:6 = \frac{{21}}{8} \times \frac{1}{6} = \frac{{21 \times 1}}{{8 \times 6}} = \frac{{7 \times 3 \times 1}}{{8 \times 3 \times 2}} = \frac{7}{{16}}$

3 tháng 3 2017

2 tk m nhé

28 tháng 5 2020

Tính tất cả ra thì được:

\(=\frac{\frac{973}{60}}{\frac{139}{60}}:\frac{\frac{1255}{221}}{\frac{1506}{221}}+\frac{5858}{5050}\)

\(=\frac{\frac{139}{60}}{\frac{973}{60}}.\frac{\frac{1506}{221}}{\frac{1255}{221}}+\frac{5858}{5050}\)

Tính tử và mẫu dần rồi ra ( phần này dễ mà )

Ta được: ( mình chỉ lấy 2 chữ số phần thập phân thôi )

\(=\frac{1578}{9209}+\frac{5858}{5050}\)

 = 133/100

End 

24 tháng 3 2019

a) \(\frac{14}{21}+1-\left|\frac{1}{3}-1\right|\)

\(=\frac{2}{3}+1-\frac{2}{3}\)

\(=1+\left(\frac{2}{3}-\frac{1}{3}\right)\)

\(=1\)

b) \(\frac{1}{3}-\left|\frac{-1}{4}+\frac{5}{6}\right|-\left|\frac{-7}{12}\right|\)

\(=\frac{1}{3}-\frac{7}{12}-\frac{7}{12}\)

\(=-\frac{5}{6}\)

24 tháng 3 2019

Các câu khác làm tương tự thôi :))

10 tháng 6 2020

\(\sqrt{\frac{9}{\sqrt{14+4\sqrt{6}}}}-\sqrt{\frac{9}{\sqrt{14-4\sqrt{6}}}}\)

\(=\sqrt{\frac{9}{\sqrt{\left(\sqrt{12}\right)^2+2\cdot\sqrt{12}\cdot\sqrt{2}+\left(\sqrt{2}\right)^2}}}-\sqrt{\frac{9}{\sqrt{\left(\sqrt{12}\right)^2-2\cdot\sqrt{12}\cdot\sqrt{2}+\left(\sqrt{2}\right)^2}}}\)

\(=\sqrt{\frac{9}{\sqrt{12}+\sqrt{2}}}-\sqrt{\frac{9}{\sqrt{12}-\sqrt{2}}}\)

\(=\frac{3}{\sqrt{\sqrt{12}+\sqrt{2}}}-\frac{3}{\sqrt{\sqrt{12}-\sqrt{2}}}=\frac{3\left(\sqrt{\sqrt{12}-\sqrt{2}}\right)-3\left(\sqrt{\sqrt{12}+\sqrt{2}}\right)}{\left(\sqrt{\sqrt{12}+\sqrt{2}}\right)\left(\sqrt{\sqrt{12}-\sqrt{2}}\right)}\)

\(=\frac{3\sqrt{\sqrt{12}-\sqrt{2}}-3\sqrt{\sqrt{12}+\sqrt{2}}}{\left(\sqrt{\sqrt{12}+\sqrt{2}}\right)\left(\sqrt{\sqrt{12}-\sqrt{2}}\right)}\)

\(=\frac{3\sqrt{\sqrt{12}-\sqrt{2}}-3\sqrt{\sqrt{12}+\sqrt{2}}}{\sqrt{12-2}}\)

\(=\frac{3\sqrt{\sqrt{12}-\sqrt{2}}-3\sqrt{\sqrt{12}+\sqrt{2}}}{\sqrt{10}}\)

\(=\frac{3\left(\sqrt{2\sqrt{3}-\sqrt{2}}-\sqrt{2\sqrt{3}+\sqrt{2}}\right)}{\sqrt{10}}\)

\(=\frac{3}{\sqrt{10}}\)

10 tháng 10 2016

\(\sqrt{\frac{9}{\sqrt{14+4\sqrt{6}}}}-\sqrt{\frac{9}{\sqrt{14-4\sqrt{6}}}}\)

\(=\sqrt{\frac{9}{\sqrt{\left(\sqrt{12}\right)^2+2\cdot\sqrt{12}\cdot\sqrt{2}+\left(\sqrt{2}\right)^2}}}-\sqrt{\frac{9}{\sqrt{\left(\sqrt{12}\right)^2-2\cdot\sqrt{12}\cdot\sqrt{2}+\left(\sqrt{2}\right)^2}}}\)

\(=\sqrt{\frac{9}{\sqrt{12}+\sqrt{2}}}-\sqrt{\frac{9}{\sqrt{12}-\sqrt{2}}}\)

\(=\frac{3}{\sqrt{\sqrt{12}+\sqrt{2}}}-\frac{3}{\sqrt{\sqrt{12}-\sqrt{2}}}=\frac{3\left(\sqrt{\sqrt{12}-\sqrt{2}}\right)-3\left(\sqrt{\sqrt{12}+\sqrt{2}}\right)}{\left(\sqrt{\sqrt{12}+\sqrt{2}}\right)\left(\sqrt{\sqrt{12}-\sqrt{2}}\right)}\)

\(=\frac{3\sqrt{\sqrt{12}-\sqrt{2}}-3\sqrt{\sqrt{12}+\sqrt{2}}}{\left(\sqrt{\sqrt{12}+\sqrt{2}}\right)\left(\sqrt{\sqrt{12}-\sqrt{2}}\right)}\)

\(=\frac{3\sqrt{\sqrt{12}-\sqrt{2}}-3\sqrt{\sqrt{12}+\sqrt{2}}}{\sqrt{12-2}}\)\(=\frac{3\sqrt{\sqrt{12}-\sqrt{2}}-3\sqrt{\sqrt{12}+\sqrt{2}}}{\sqrt{10}}\)

\(=\frac{3\left(\sqrt{2\sqrt{3}-\sqrt{2}}-\sqrt{2\sqrt{3}+\sqrt{2}}\right)}{\sqrt{10}}\)

bí....!!!

18 tháng 8 2020

[\(\frac{-75}{59}\).\(\frac{-107}{93}\)]\(\frac{31}{50}\)=\(\frac{2675}{1829}\).\(\frac{31}{50}\)=\(\frac{107}{118}\)

18 tháng 8 2020

\(\left[\frac{1\frac{11}{31}\cdot4\frac{3}{7}-\left(15-6\frac{1}{3}\cdot\frac{2}{19}\right)}{4\frac{5}{6}+\frac{1}{6}\left(12-5\frac{1}{3}\right)}\cdot\left(-1\frac{14}{93}\right)\right]\cdot\frac{31}{50}\)

\(=\left[\frac{\frac{42}{31}\cdot\frac{31}{7}-\left(15-\frac{19}{3}\cdot\frac{2}{19}\right)}{4\frac{5}{6}+\frac{1}{6}\left(12-\frac{16}{3}\right)}\cdot\left(-\frac{107}{93}\right)\right]\cdot\frac{31}{50}\)

\(=\left[\frac{6-\left(15-\frac{2}{3}\right)}{\frac{29}{6}+\frac{1}{6}\cdot\frac{20}{3}}\cdot\left(-\frac{107}{93}\right)\right]\cdot\frac{31}{50}\)

\(=\left[\frac{6-15+\frac{2}{3}}{\frac{29}{6}+\frac{10}{9}}\cdot\left(-\frac{107}{93}\right)\right]\cdot\frac{31}{50}\)

\(=\left[\frac{-\frac{25}{3}}{\frac{107}{18}}\cdot\left(-\frac{107}{93}\right)\right]\cdot\frac{31}{50}\)

\(=\left[\left(-\frac{150}{107}\right)\cdot\left(-\frac{107}{93}\right)\right]\cdot\frac{31}{50}=\frac{50}{31}\cdot\frac{31}{50}=1\)

7 tháng 10 2016

\(12.\left(\frac{3}{4}-5x\right)=12.\frac{3}{4}-12.5x=9-12.5x=9-60x\)

\(9-60x=\frac{4}{5}-3x\), Rồi bạn làm bước cuối, chuyển vế

\(2\frac{5}{7}+\frac{3}{14}-\frac{6}{7}+0,5+\frac{9}{14}=\frac{19}{7}+\frac{3}{14}-\frac{6}{7}+0,5+\frac{9}{14}\)

\(=\left(\frac{19}{7}-\frac{6}{7}\right)+\left(\frac{3}{14}+\frac{9}{14}\right)+0,5=1+\frac{6}{7}+0,5=\frac{33}{14}\)