a) 2/5 + 1/2 + 7/10

= 4/10 + 5/10 + 7/10

= 9/10 + 7/10

= 16/10 = 8/5

b) 4/9 + 11/8 - 5/6

= 32/72 + 99/72 - 60/72

= 191/72

c) 9/20 - 8/15 x 5/12

= 9/20 - 2/9

= 41/180

d) 2/3 : 4/5 : 7/12

= 5/6 : 7/12

= 10/7

a,2/5+1/2+7/10

=4/10+5/10+7/10

=16/10

=8/5

b,4/9+11/8-5/6

=32/72+99/72-5/6

=131/72-5/6

=131/72-60/72

=71/72

c,9/20-8/15x5/12

=9/20-2/9

=41/180

d,2/3:4/5:7/12

=2/5x5/4x12/7

=6/7

a, 13/6+5/8 : -3/4 - 7/12.4

= 13/6 + -5/6-7/3

=8/6-7/3

= -6/6

= -1

b, ( 73/5 - 21/3) + ( 4/3-43/5 )

= 73/5-21/3+4/3-43/5

=( 73/5-43/5)-(21/3-4/3)

= 6-17/3

=1/3

c, 7/5.4/9 +7/5: 9/16- 14/10.2/9

= 7/5.4/9 +7/5.16/9 - 14/45

=7/5.(4/9+16/9)-14/45

=7/5.20/9-14/45

= 140/45 - 14/45

= 126/45

Xong rùi nè! Nhưng bạn kiểm tra lại giùm nhé vì làm vào ban đêm nên hơi bất tiện

Trời ạ. 7 3/5 chứ k phải 73/5 -_-

ghi rõ thêm từ và nhé!

a.\(y:\dfrac{4}{5}=\dfrac{11}{8}\)

\(y=\dfrac{11}{8}\times\dfrac{4}{5}\)

\(y=\dfrac{11}{10}\)

b.\(\dfrac{11}{3}-y=\dfrac{1}{9}\)

\(y=\dfrac{11}{3}-\dfrac{1}{9}\)

\(y=\dfrac{32}{9}\)

c.\(\dfrac{1}{7}\times x=\dfrac{8}{5}\)

\(x=\dfrac{8}{5}:\dfrac{1}{7}\)

\(x=\dfrac{56}{5}\)

\(y=\dfrac{11}{8}.\dfrac{4}{5}\)

\(y=\dfrac{44}{40}\)

\(x=\dfrac{11}{3}-\dfrac{1}{9}\)

\(x=\dfrac{99-3}{27}=\dfrac{96}{27}\)

\(x=\dfrac{8}{5}:\dfrac{1}{7}\)

\(x=\dfrac{56}{5}\)

a)\(y=\dfrac{4}{5}\times\dfrac{11}{8}=\dfrac{44}{40}=1\dfrac{4}{40}\)

b)\(y=\dfrac{11}{3}-\dfrac{1}{9}=\dfrac{33}{9}-\dfrac{1}{9}=\dfrac{32}{9}\)

c)\(x=\dfrac{8}{5}\times7=\dfrac{56}{5}\)

a,3/7 : 5/8 = 24/56 : 35/56 = 24/35

b, 8/7 : 3/4 = 32/28 : 21/28 = 32/21

c, 1/3: 1/2 = 2/6 : 3/6 =2/3

\(a;\frac{3}{7}+\frac{2}{3}=\frac{9}{21}+\frac{14}{21}=\frac{23}{21}\)

\(b;\frac{8}{7}-\frac{12}{28}\times\frac{7}{3}=\frac{8}{7}-\frac{3}{7}\times\frac{7}{3}=\frac{8}{7}-1=\frac{8}{7}-\frac{7}{7}=\frac{1}{7}\)

\(c;\frac{5}{6}\times3=\frac{15}{6}=\frac{5}{2}\)

\(d;\frac{3}{2}:\frac{7}{15}=\frac{3}{2}\times\frac{15}{7}=\frac{45}{14}\)

a) 3/7+2/3=9/21+14/21=23/21

b) 8/7-12/28*7/3=8/7-1=8/7-7/7-1/7

c) 5/6*3=5/2

d) 3/2:7/15=3/2*15/7=45/14

a,\(\frac{7}{10}\cdot\frac{4}{9}+\frac{3}{10}\cdot\frac{4}{9}-1\frac{7}{9}\)

\(=\frac{14}{45}+\frac{2}{15}-\frac{16}{9}\)

\(=\frac{14}{45}+\frac{6}{45}-\frac{80}{45}\)

\(=\frac{-60}{45}=\frac{-4}{3}\)

b,\(\frac{-5}{6}+\frac{4}{9}\cdot\left(\frac{5}{4}-\frac{2}{3}\right)\cdot\left(-3\right)^2+\frac{5}{9}\cdot30\%\)

\(=\frac{-5}{6}+\frac{4}{9}\cdot\left(\frac{7}{12}\right)\cdot9+\frac{5}{9}\cdot\frac{3}{10}\)

\(=\frac{-5}{6}+\frac{7}{3}+\frac{1}{6}\)

\(=\frac{-5}{6}+\frac{14}{6}+\frac{1}{6}\)

=\(=\frac{10}{6}=\frac{5}{3}\)