\(a,11\dfrac{3}{4}-\left(6\dfrac{5}{6}-4\dfrac{1}{2}\right)+1\dfrac{2}{3}\)

\(=\dfrac{47}{4}-\left(\dfrac{41}{6}-\dfrac{9}{2}\right)+\dfrac{5}{3}\)
\(=\dfrac{47}{4}-\left(\dfrac{41}{6}-\dfrac{27}{6}\right)+\dfrac{5}{3}\)

\(=\dfrac{47}{4}-\dfrac{14}{6}+\dfrac{5}{3}\)

\(=\dfrac{47}{4}-\dfrac{7}{3}+\dfrac{5}{3}\)

\(=\dfrac{47}{4}-\left(\dfrac{7}{3}+\dfrac{5}{3}\right)\)

\(=\dfrac{47}{4}-\dfrac{12}{3}\)

\(=\dfrac{47}{4}-4\)

\(=\dfrac{47}{4}-\dfrac{16}{4}\)

\(=\dfrac{31}{4}\)

c) Ta có: \(4\dfrac{3}{7}:\left(\dfrac{7}{5}\cdot4\dfrac{3}{7}\right)\)

\(=\dfrac{31}{7}:\left(\dfrac{7}{5}\cdot\dfrac{31}{7}\right)\)

\(=\dfrac{31}{7}:\dfrac{31}{5}\)

\(=\dfrac{5}{7}\)

1.a,=(54+45+1).113

=100.113

=11300

b,=(3/7+8/14)+(4/9+10/18)

=1+1

=2

2.a,=13/10+1/3

=49/30

b,=12/9.(1/12+1/6)

=12/9.1/4

=1/3

c,=3/4.3/2

=9/8

d,=3/2-1/3

=7/6

1:tính bằng cách thuận tiện nhất:

a)54 x 113 + 45 x 113 + 113

= 54 x 113 + 45 x 113 + 113x1

=113 x(54+45+1)

= 113x100

=1300

 b)3/7 + 4/9 + 8/14 + 10/18

=(3/7+8/14)+(4/9+10/18)

=    1           + 1

=2

a: \(=\dfrac{10-6}{15}\cdot\dfrac{1}{3}=\dfrac{4}{45}\)

b: \(=\dfrac{10+6}{15}\cdot\dfrac{1}{3}=\dfrac{16}{45}\)

c: \(=\dfrac{4+3}{6}\cdot\dfrac{4}{3}=\dfrac{7\cdot4}{6\cdot3}=\dfrac{28}{18}=\dfrac{14}{9}\)

d: \(=\dfrac{20-14}{35}\cdot\dfrac{9}{4}=\dfrac{6}{35}\cdot\dfrac{9}{4}=\dfrac{54}{140}=\dfrac{27}{70}\)

a (2/3 - 2/5 ) nhân 1/3

C1) 

=4/15 x 1/3

= 4/45

C2)

2/3 x 1/3 - 2/5 x 1/3

= 2/9 - 2/15

= 4/45

b (2/3 + 2/5 )nhân 1/3

GIỐNG CÂU A

c (2/3 + 1/2 ) chia 3/4

C1) =7/6 : 3/4

= 14/9

C2) 

2/3 : 3/4 + 1/2 : 3/4

= 8/9 + 2/3

= 14/9

d(4/7 - 2/5 ) chia 4/9

C1) 

= 6/35 : 4/9

= 27/70

C2)

4/7 : 4/9 - 2/5 : 4/9

= 9/7 -9/10

= 27/70

a) C1 : \(\left(\dfrac{2}{3}-\dfrac{2}{5}\right)\times\dfrac{1}{3}=\dfrac{4}{15}\times\dfrac{1}{3}=\dfrac{4}{45}\)

    C2 : \(\left(\dfrac{2}{3}-\dfrac{2}{5}\right)\times\dfrac{1}{3}=\dfrac{2}{3}\times\dfrac{1}{3}-\dfrac{2}{5}\times\dfrac{1}{3}=\dfrac{2}{9}-\dfrac{2}{15}=\dfrac{4}{45}\)

b) C1 \(\left(\dfrac{2}{3}+\dfrac{2}{5}\right)\times\dfrac{1}{3}=\dfrac{16}{15}\times\dfrac{1}{3}=\dfrac{16}{45}\)

    C2 \(\left(\dfrac{2}{3}+\dfrac{2}{5}\right)\times\dfrac{1}{3}=\dfrac{2}{3}\times\dfrac{1}{3}+\dfrac{2}{5}\times\dfrac{1}{3}=\dfrac{2}{9}+\dfrac{2}{15}=\dfrac{16}{45}\)

c) C1 \(\left(\dfrac{2}{3}+\dfrac{1}{2}\right):\dfrac{3}{4}=\left(\dfrac{2}{3}+\dfrac{1}{2}\right)\times\dfrac{4}{3}=\dfrac{7}{6}\times\dfrac{4}{3}=\dfrac{14}{9}\)

   C2 \(\left(\dfrac{2}{3}+\dfrac{1}{2}\right):\dfrac{3}{4}=\left(\dfrac{2}{3}+\dfrac{1}{2}\right)\times\dfrac{4}{3}=\dfrac{2}{3}\times\dfrac{4}{3}+\dfrac{1}{2}\times\dfrac{4}{3}=\dfrac{8}{9}+\dfrac{2}{3}=\dfrac{14}{9}\)

d) C1 \(\left(\dfrac{4}{7}-\dfrac{2}{5}\right):\dfrac{4}{9}=\left(\dfrac{4}{7}-\dfrac{2}{5}\right)\times\dfrac{9}{4}=\dfrac{6}{35}\times\dfrac{9}{4}=\dfrac{27}{70}\)

    C2 \(\left(\dfrac{4}{7}-\dfrac{2}{5}\right):\dfrac{4}{9}=\left(\dfrac{4}{7}-\dfrac{2}{5}\right)\times\dfrac{9}{4}=\dfrac{4}{7}\times\dfrac{9}{4}-\dfrac{2}{5}\times\dfrac{9}{4}=\dfrac{36}{28}-\dfrac{9}{10}=\dfrac{27}{70}\)

Lời giải chi tiết:

Xóa nhanh đi ko CTV xóa giờ

Chia chúng nó ra

Câu dễ vậy bạn cần hỏi

a)\(=\dfrac{3}{3}+\dfrac{4}{3}=\dfrac{7}{3}\)

b)\(=\dfrac{5}{9}\times\dfrac{3}{2}=\dfrac{15}{18}=\dfrac{5}{6}\)

d)\(=\left(\dfrac{12}{8}-\dfrac{3}{8}\right)\times2=\dfrac{9}{8}\times2=\dfrac{18}{8}=\dfrac{9}{4}\)

c)\(=\dfrac{4}{3}-\dfrac{5}{6}=\dfrac{8}{6}-\dfrac{5}{6}=\dfrac{3}{6}=\dfrac{1}{2}\)

a) 1 + 4/3 = 7/3

b) 5/9 : 2/3 = 5/6

c ) 4/3 -1/3 x 5/2

= 1 x 5/2

= 5/2

d) ( 3/2 - 3/8) : 1/2

= 9/8 : 1/2

= 9/4

e) 15/16 : 3/8 x 3/4 

= 5/2 x 3/4

= 15/8

f) 7/19 x 1/3 x 7/19 x 2/3

= 7/19 x (1/3 x 2/3)

= 7/19 x 2/9

= 14/171

g) 3/5 x 8/27 x 25/3

= 3/5 x 25/3 x 8/27 

= 5 x 8/27

= 40/27

h) 1/5 + 4/11 + 4/5 + 7/11

= (1/5 + 4/5) + (4/11 + 7/11)

= 1 + 1

= 2

e)\(\dfrac{15}{16}\times\dfrac{8}{3}\times\dfrac{3}{4}=\dfrac{360}{192}=\dfrac{15}{8}\)

f) \(=\dfrac{7}{19}\times\left(\dfrac{1}{3}+\dfrac{2}{3}\right)=\dfrac{7}{19}\times\dfrac{3}{3}=\dfrac{7}{19}\)

g)\(=\dfrac{600}{120}=\dfrac{600:120}{120:120}=\dfrac{5}{1}=5\)

h)\(=\left(\dfrac{1}{5}+\dfrac{4}{5}\right)+\left(\dfrac{4}{11}+\dfrac{7}{11}\right)=\dfrac{5}{5}+\dfrac{11}{11}=1+1=2\)

\(a,=\dfrac{x^4\left(x-2\right)+2x^2\left(x-2\right)-3\left(x-2\right)}{x+4}\\ =\dfrac{\left(x-2\right)\left(x^4+2x^2-3\right)}{x+4}\\ =\dfrac{\left(x-2\right)\left(x^4-x^2+3x^2-3\right)}{x+4}\\ =\dfrac{\left(x-2\right)\left(x-1\right)\left(x^2+3\right)}{x+4}\)

\(b,=\dfrac{x^4-3x^2-x^2+3}{x^4-x^2+7x^2-7}=\dfrac{\left(x^2-3\right)\left(x^2-1\right)}{\left(x^2+7\right)\left(x^2-1\right)}=\dfrac{x^2-3}{x^2+7}\\ c,=\dfrac{\left(x^3-1\right)\left(x+1\right)}{x^2\left(x^2+x+1\right)+\left(x^2+x+1\right)}\\ =\dfrac{\left(x-1\right)\left(x^2+x+1\right)\left(x+1\right)}{\left(x^2+1\right)\left(x^2+x+1\right)}=\dfrac{x^2-1}{x^2+1}\)

`a, 3/4 + 1/2 xx 7/2`

`= 3/4 + 7/4`

`=10/4`

`=5/2`

`b, 6/15 - 1/3 : 5/3`

`= 6/15 - 1/3 xx 3/5`

`= 6/15 - 3/15`

`= 3/15`

`=1/5`

`c, x-4/9 = 3/7 : 9/4`

`=> x-4/9= 3/7 xx 4/9`

`=> x-4/9= 12/63`

`=> x-4/9=4/21`

`=> x= 4/21 +4/9`

`=>x= 40/63`

`d, 7/9 xx 3/5 -1/2=1/5`

`->` sao lại bằng có `x` ko vậy ạ?

`a,`

`3/4+1/2 \times 7/2=3/4+7/4=10/4=5/2`

`b,`

`6/15 - 1/3 \div 5/3=6/15-1/5=1/5`

`c,` Tìm x?

`x-4/9=3/7 \div 9/4`

`x-4/9=4/21`

`x=4/21+4/9`

`x=40/63`

`d, 7/9x \times 3/5-1/2=1/5`

`7/9x \times 3/5=1/5+1/2`

`7/9x \times 3/5=7/10`

`7/9x=7/10 \div 3/5`

`7/9x=7/6`

`x=7/6 \div 7/9=3/2`