Bài 1: 

150/120+15/27=5/4+5/9=45/36+20/36=65/36

42/49+56/84=6/7+2/3=9/21+14/21=23/21

a) 9171 = 9000 + 100 + 70 = 1

3082 = 3000 + 80 +2

7006 = 7000 + 6

b) 7000 + 300 + 50 + 1 = 7351

6000 + 200 + 3 = 6203

6000 + 200 + 30 = 6230

5000 + 2 = 5002

\(\dfrac{7}{12}=\dfrac{3}{12}+\dfrac{4}{12}=\dfrac{1}{4}+\dfrac{1}{3}\)

\(\dfrac{13}{27}=\dfrac{9}{27}+\dfrac{4}{27}=\dfrac{1}{3}+\dfrac{4}{27}\)

\(\dfrac{7}{12}\) = \(\dfrac{1+6}{12}\) = \(\dfrac{1}{12}\) + \(\dfrac{6}{12}\) = \(\dfrac{1}{12}\) + \(\dfrac{1}{2}\)

\(\dfrac{7}{12}\) = \(\dfrac{3+4}{12}\) = \(\dfrac{3}{12}\) + \(\dfrac{4}{12}\) = \(\dfrac{1}{4}\) + \(\dfrac{1}{3}\)

\(\dfrac{13}{27}\) = \(\dfrac{1+12}{27}\) = \(\dfrac{1}{27}\) + \(\dfrac{12}{27}\) = \(\dfrac{1}{27}\) + \(\dfrac{4}{9}\)

\(\dfrac{13}{27}\) = \(\dfrac{4+9}{27}\) = \(\dfrac{4}{27}\) + \(\dfrac{9}{27}\) = \(\dfrac{4}{27}\) + \(\dfrac{1}{3}\)

\(\dfrac{13}{27}\) = \(\dfrac{6+7}{27}\) = \(\dfrac{6}{27}\) + \(\dfrac{7}{27}\) = \(\dfrac{2}{9}\) +  \(\dfrac{7}{27}\)

a, \(\dfrac{7}{12}=\dfrac{6+1}{12}=\dfrac{6}{12}+\dfrac{1}{12}=\dfrac{6}{6\times2}+\dfrac{1}{12}=\dfrac{1}{2}+\dfrac{1}{12}\)

b, \(\dfrac{13}{27}=\dfrac{12+1}{27}=\dfrac{12}{27}+\dfrac{1}{27}=\dfrac{3\times4}{3\times9}+\dfrac{1}{27}=\dfrac{4}{9}+\dfrac{1}{27}\)

đây là đáp án của mình ạ.

a) 608 292 = 600 000 + 8 000 + 200 + 90 + 2

815 036 = 800 000 + 10 000 + 5 000 + 30 + 6

5 240 601 = 5 000 000 + 200 000 + 40 000 + 600 + 1

b)

50 000 + 6 000 + 300 + 20 + 7 = 56 327

800 000 + 2 000 + 100 + 40 + 5 = 802 145

3 000 000 + 700 000 + 5 000 + 90 = 3 705 090

A. 3/14 >1/84

B. 5/36 >3/28

7/   

a, 23/7 

b, 92/20

8/    =

a) 2 894 = 2 000 + 800 + 90 + 4

7 205 = 7 000 + 200 + 5

5 668 = 5 000 + 600 + 60 + 8

3 327 = 3 000 + 300 + 20 + 7

b)

4 000 + 700 + 40 + 2 = 4 742

5 000 + 500 + 50 + 5 = 5 555

2 000 + 600 + 40 + 8 = 2648

3 000 + 900 + 8 = 3 908

9171 = 9000 + 100 + 70 + 1

3082 = 3000 + 80 +2

7006 = 7000 + 6