`a: =(7/3-4/3)+11/5=16/5`

`b: =(18/13-5/13)+55/46=1+55/46=101/46`

`c: =27/25-4/9-2/25+5/9=(27/25-2/25)+(5/9-4/9)=1+1/9=10/9`

a) \(...=16.\left(36-37\right)=16.\left(-1\right)=-16\)

b) \(...=9.3+9.50=9.\left(3+50\right)=9.53=477\)

c) \(...=2.\left(\left(5.16-18\right)+36:18\right)=2.\left(70+2\right)=2.72=144\)

d) \(...=5\left(48:8+44\right)=5\left(6+44\right)=5.50=250\)

e) \(...=20-6=14\) 

f) \(...=50+13-2=61\)

Cô tick xanh cho bạn Đức Trí, các câu khác em làm theo bạn vì bạn làm đúng còn câu c em làm theo cô nhé.

Câu c, 

    2.(5.16 - 18) + 36:18.2

= 2.(80 - 18) + 2.2

= 2.62 + 4

= 128

d) 48 : 8 . 5 + 5 . 44

= 6 . 5 + 5 . 44

= 5 . (6 + 44)

= 5 . 50

= 250

e) 5 . 4 - 18 : 3

= 20 - 6

= 14

f) 2 . 25 + 169 : 13 - 54 : 27

= 50 + 13 - 2

= 61

a) \(\dfrac{7}{-25}+\dfrac{8}{25}=\dfrac{-7}{25}+\dfrac{8}{25}=\dfrac{1}{25}\)

\(\dfrac{4}{5}+\dfrac{4}{-18}=\dfrac{4}{5+\left(-18\right)}=\dfrac{4}{-13}=\dfrac{-4}{13}\)

\(\dfrac{7}{21}+\dfrac{9}{-36}=\dfrac{1}{3}+\dfrac{1}{-4}=\dfrac{1}{3+\left(-4\right)}=\dfrac{1}{-1}=1\)

b) \(\dfrac{12}{20}-\dfrac{2}{5}=\dfrac{12}{20}+\left(\dfrac{-2}{5}\right)=\dfrac{3}{5}+\dfrac{-2}{5}=\dfrac{3+\left(-2\right)}{5}=\dfrac{1}{5}\)

\(\dfrac{2}{3}-\dfrac{-5}{6}=\dfrac{2}{3}+\dfrac{5}{6}=\dfrac{4}{6}+\dfrac{5}{6}=\dfrac{9}{6}=\dfrac{3}{2}\)

\(6-\dfrac{3}{20}=6+\dfrac{-3}{20}=\dfrac{60}{60}+\dfrac{-9}{60}=\dfrac{51}{60}\)

c) \(\dfrac{2}{21}.\dfrac{-7}{3}=\dfrac{2.\left(-1\right)}{7.3}=\dfrac{-2}{21}\)

\(\dfrac{27}{28}.\left(-21\right)=\dfrac{27.\left(-21\right)}{28}=\dfrac{-567}{28}\)

\(\dfrac{-15}{7}.\dfrac{-14}{25}=\dfrac{-3.\left(-2\right)}{1.5}=\dfrac{6}{5}\)

Tách từng câu ra giùm, như này ai giải nổi:)))))

a: \(=\dfrac{2}{3}+\dfrac{19}{35}=\dfrac{70+57}{105}=\dfrac{127}{105}\)

b: \(=\dfrac{2}{7}+\dfrac{2}{5}=\dfrac{24}{35}\)

c: \(=\dfrac{7}{12}-\dfrac{14}{2}=\dfrac{7-84}{12}=\dfrac{-77}{12}\)

d: \(=\dfrac{-15}{60}-\dfrac{1}{8}=-\dfrac{3}{8}\)

e: \(=-\dfrac{12}{72}+\dfrac{1}{18}=\dfrac{-3}{18}+\dfrac{1}{18}=\dfrac{-2}{18}=\dfrac{-1}{9}\)

a: \(=3\sqrt{3}-2\sqrt{3}+4\sqrt{3}-5\sqrt{3}=2\sqrt{3}\)