⁵/₂ x ²/₇ + ³/₇ = ⁸/₇

Chúc bạn học tốt !!!

= 8/7 nha

8/7

học tốt nha

TL

4/3+4/7x2x5

=4/3+40/7

=148/21

nha

HT

4 phần 3 + 4 phần 7 x 2 x 5

= 4/3 + 40/7 

= 148/21

Câu A nha bé vì nhân chéo lên sẽ là như vậy 

a, Ta có : \(-\dfrac{3}{2}-2x+\dfrac{3}{4}=-2\)

\(\Rightarrow-2x=-2+\dfrac{3}{2}-\dfrac{3}{4}=-\dfrac{5}{4}\)

\(\Rightarrow x=\dfrac{5}{8}\)

Vậy ...

b, Ta có : \(\left(-\dfrac{2}{3}x-\dfrac{3}{5}\right)\left(-\dfrac{3}{2}-\dfrac{10}{3}\right)=\dfrac{2}{5}\)

\(\Rightarrow-\dfrac{29}{6}\left(-\dfrac{2}{3}x-\dfrac{3}{5}\right)=\dfrac{2}{5}\)

\(\Rightarrow-\dfrac{2}{3}x-\dfrac{3}{5}=-\dfrac{12}{145}\)

\(\Rightarrow-\dfrac{2}{3}x=-\dfrac{12}{145}+\dfrac{3}{5}=\dfrac{15}{29}\)

\(\Rightarrow x=-\dfrac{45}{58}\)

Vậy...

- Tham khảo thanh này để đánh nha bạn ;-;

a) Ta có: \(\dfrac{-3}{2}-\dfrac{2x+3}{4}=-2\)

\(\Leftrightarrow\dfrac{-6-2x-3}{4}=-2\)

\(\Leftrightarrow-2x-9=-8\)
\(\Leftrightarrow-2x=1\)

hay \(x=-\dfrac{1}{2}\)

b) Ta có: \(\left(-\dfrac{2}{3}x-\dfrac{3}{5}\right)\left(\dfrac{3}{2}-\dfrac{10}{3}\right)=\dfrac{2}{5}\)

\(\Leftrightarrow\dfrac{-2}{3}x-\dfrac{3}{5}=\dfrac{2}{5}:\dfrac{-11}{6}=-\dfrac{12}{55}\)

\(\Leftrightarrow\dfrac{-2}{3}x=\dfrac{21}{55}\)

hay \(x=-\dfrac{63}{110}\)

                                                            Bài giải

\(\frac{2}{3}+\frac{3}{4}+\frac{4}{5}=\frac{40}{60}+\frac{45}{60}+\frac{48}{60}=\frac{133}{60}\)

\(\frac{8}{5}+\frac{7}{6}+\frac{10}{9}+\frac{1}{2}=\frac{144}{90}+\frac{105}{90}+\frac{100}{90}+\frac{45}{90}=\frac{394}{90}\)

\(\frac{15}{17}-\frac{11}{13}+\frac{3}{26}=\frac{390}{442}+\frac{374}{442}+\frac{51}{442}=\frac{815}{442}\)

\(\frac{9}{12}\text{ x }\frac{4}{3}\text{ : }\frac{8}{5}=\frac{9}{12}\text{ x }\frac{4}{3}\text{ x }\frac{5}{8}=\frac{9\text{ x }4\text{ x }5}{12\text{ x }3\text{ x }8}=\frac{5}{8}\)

\(\frac{4}{5}\text{ x }\frac{15}{8}\text{ : }\frac{5}{7}=\frac{4}{5}\text{ x }\frac{15}{8}\text{ x }\frac{7}{5}=\frac{4\text{ x }15\text{ x }7}{5\text{ x }8\text{ x }5}=\frac{21}{10}\)

\(\frac{2}{3}+\frac{3}{4}+\frac{4}{5}=\frac{40}{60}+\frac{45}{60}+\frac{48}{60}=\frac{133}{60}\) 

\(\frac{8}{5}+\frac{7}{6}+\frac{10}{9}+\frac{1}{2}=\frac{144}{90}+\frac{105}{90}+\frac{100}{90}+\frac{45}{90}=\frac{197}{45}\)

\(\frac{15}{17}-\frac{11}{13}+\frac{1}{26}=\frac{390}{442}+\frac{374}{442}+\frac{51}{442}=\frac{815}{442}\)

\(\frac{9}{12}\times\frac{4}{3}:\frac{8}{5}=1:\frac{8}{5}=\frac{5}{8}\)

\(\frac{4}{5}\times\frac{15}{8}:\frac{5}{7}=\frac{3}{2}:\frac{5}{7}=\frac{21}{10}\)

khó cậu ạ

đáp số là 278 phần 315

278 phần 315

80/84=20/21

Học tốt 

\(\frac{80}{84}=\frac{20}{21}\)

80/84 : 4/4 = 20/21

Chúc bạn học tốt