a) \(\frac{47}{3}:3-\frac{37}{3}:3+\frac{5}{3}=\left(\frac{47}{3}-\frac{37}{3}\right):3+\frac{5}{3}\)

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

b) \(\frac{3}{5}:\frac{7}{9}.\frac{7}{9}+\frac{7}{5}:2=\frac{3}{5}+\frac{7}{10}=\frac{13}{10}\)

thank you 

a: =428(36+64)=42800

b: =512(47-37)=5120

c: =72x100=7200

\(428×(36+64)\)

\(=428×100\)

\(=42800\)

\(512×(47-37)\)

\(=512×10\)

\(=5120\)

\(72×(4×25)\)

\(=72×100\)

\(=7200\)

\(\left(\dfrac{4+5}{9}\right)\text{×}\dfrac{3}{7}\)

\(=1\text{×}\dfrac{3}{7}\)

\(=\dfrac{3}{7}\)

a, 428 x 36 + 64 x 428

=  428 x (36 + 64)

=  428 x 100

= 42800

b, 512 x 47 - 37 x 512

=  512 x (47 - 37)

= 512 x 10

= 5120

câu này mik bị lú nên hok lm

d) 4/9 x 3/7 + 5/9 x 3/7

= 3/7 x (4/9 + 5/9)

= 3/7 x 1

= 3/7

( 1/10 + 2/9 + 3/8 + 4/7 + 5/6 + 1/6 + 3/7 + 5/8 + 7/9 + 9/10 ) * 48

= [ ( 1/10 + 9/10 ) + ( 2/9 + 7/9 ) + ( 3/8 + 5/8 ) + ( 4/7 + 3/7 ) + ( 5/6 + 1/6 ) ] * 48

=( 1 + 1 + 1 + 1 +  ) *48

=5 * 48

= 240

a,3/5*7/9+11/9*3/5-3/10=3/5*(7/9+11/9)-3/10

=3/5*18/9-3/10

=3/5*2-3/10

=6/5-3/10

=12/10-3/10

=9/10

b,14/13:1/2+3/13*2-2*7/13=14/13*2+3/13*2-2*7/13

=2*(14/13+3/13-7/13)

=2*10/13

=20/13

a/ ( 7/9 + 11/9 ) x 3/5 - 3/10

 =    2 x 3/5 - 3/10

=    6/5  - 3/10

 =    9/10

b/ 14/13 :  1/2 + 3/13 x 2 - 2 x 7/13

14/13 x 2/1 + 3/13 x 2 - 2 x 7/13

2 x ( 14/13 + 3/13 - 7/13 )

2 x 10/13

20/13

1*3+5*7+9*11+...+99*101

A,  4/9 + [3/8 + 5/8 ]

    =4/9 + 1

    =13/9

B,  [3/7+4/7]+2/3

=1+2/3

=5/3

\(a)\frac{4}{9}+\frac{3}{8}+\frac{5}{8}=\frac{4}{9}+(\frac{3}{8}+\frac{5}{8})=\frac{4}{9}+1=\frac{4+9}{9}=\frac{13}{9}\)

\(b)\frac{3}{7}+\frac{2}{3}+\frac{4}{7}=(\frac{3}{7}+\frac{4}{7})+\frac{2}{3}=1+\frac{2}{3}=\frac{3+2}{3}=\frac{5}{3}\)

\(a,\frac{4}{9}+\frac{3}{8}+\frac{5}{8}\)

\(=\left(\frac{3}{8}+\frac{5}{8}\right)+\frac{4}{9}\)

\(=1+\frac{4}{9}\)

\(=\frac{9}{9}+\frac{4}{9}=\frac{13}{9}\)

\(b,\frac{3}{7}+\frac{2}{3}+\frac{4}{7}\)

\(=\left(\frac{3}{7}+\frac{4}{7}\right)+\frac{2}{3}\)

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

\(=\frac{3}{3}+\frac{2}{3}=\frac{5}{3}\)

\(a)\frac{3}{5}\times\frac{2}{5}+\frac{3}{4}\times\frac{3}{5}\)

\(=\frac{3}{5}\times\left(\frac{2}{5}+\frac{3}{4}\right)\)

\(=\frac{3}{5}\times\left(\frac{8}{20}+\frac{15}{20}\right)\)

\(=\frac{3}{5}\times\frac{23}{20}\)

\(=\frac{69}{100}\)

\(b)\frac{5}{9}\times\frac{7}{3}\times\frac{9}{5}\)

\(=\left(\frac{5}{9}\times\frac{9}{5}\right)\times\frac{7}{3}\)

\(=1\times\frac{7}{3}\)

\(=\frac{7}{3}\)

a) 3/5x2/5+3/4x3/5

=2/5+3/4x(3/5)

=69/100

.B chịu

a. = 69/100 b , 7/3 nhé hok tốt

\(\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\left(\dfrac{3}{5}+\dfrac{2}{5}\right)+\left(\dfrac{3}{8}+\dfrac{4}{8}+\dfrac{1}{8}\right)+\left(\dfrac{1}{9}+\dfrac{8}{9}\right)=1+1+1+1=4\)

(2/7 + 5/7) + (3/5 + 2/5) + (3/8 + 4/8 + 1/8) + (1/9 + 8/9 )

= 1  +       1                   +         1             +        1         =  4

1 ] 2/3 : 1/2 + 1/3 : 1/2

= 2/3 x 2/1 + 1/3 x 2/1

= 2/1 x ( 2/3 + 1/3 )

= 2 x 1

= 2

2 ] 3/10 : 7/6 : 3/7

= 3/10 x 6/7 x 7/3

= 3 x 6 x 7 / 10 x 7 x 3 

= [ tách 6 và 10 ] 3 x 3 x 2 x 7 / 2 x 5 x 7 x 3

= [ Gạch chéo các số trùng nhau trong tử số và mẫu số , đó là rút gọn ]

= 3 / 5

3 ] 4/5 x 7/9 : 7/5

= 4/5 x 7/9 x 5/7

[ làm  như phép tính 2 ]

4 ] ( 1 - 1/2 ) x ( 1 - 1/3 ) x ( 1 - 1/4 ) x ( 1 - 1/5 )

= 1/2 x 2/3 x 3/4 x 4/5

= 1 x 2 x 3 x 4 / 2 x 3 x 4 x 5

= [ gạch các số trùng nhau trong tử số và mẫu số ] 

= 1/5

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

bằng3/2 nhân 1/2 + 3/1 nhân 1/2 

bằng3/4+3/2 bằng 3/4 + 6/4 bằng 9/4

ko bít

\(\frac{9}{10}\)+\(\frac{7}{9}\)+\(\frac{5}{8}\)+\(\frac{3}{7}+\frac{3}{5}+\frac{2}{5}+\frac{4}{7}+\frac{3}{8}+\frac{2}{9}+\frac{1}{10}\)

\(=\left(\frac{9}{10}+\frac{1}{10}\right)+\left(\frac{7}{9}+\frac{2}{9}\right)+\left(\frac{5}{8}+\frac{3}{8}\right)\)\(+\left(\frac{3}{7}+\frac{4}{7}\right)+\left(\frac{3}{5}+\frac{2}{5}\right)\)

\(=1+1+1+1+1\)

\(=5\)

9/10 + 7/9 + 5/8 + 3/7 + 3/5 + 2/5 + 4/7 + 3/8 + 2/9 + 1/10

= ( 9/10 + 1/10 ) + ( 7/9 + 2/9 ) + ( 5/8 + 3/8 ) + ( 3/7 + 4/7 ) + ( 3/5 + 2/5 )

= 1 + 1 + 1 + 1 + 1

= 5

= (9/10+ 1/10 )+(7/9 + 2/9)+( 5/8 +3/8)+(3/5 +2/5)

=1+1+1+1=4