\(\frac{7}{24}+\frac{13}{6}=\frac{7}{24}+\frac{52}{24}=\frac{59}{24}\)

\(\frac{12}{49}-\frac17=\frac{12}{49}-\frac{7}{49}=\frac{5}{49}\)

\(\frac58\times\frac{24}{25}=\frac{5\times24}{8\times25}=\frac{150}{200}=\frac{30}{40}\)

\(\frac{38}{21}:\frac{19}{3}=\frac{38}{21}\times\frac{3}{19}=\frac{114}{399}\)

34287 x 65 = 1224655

557130: 42 = 13265

\(\frac{7}{24}+\frac{13}{6}=\frac{7}{24}+\frac{52}{24}=\frac{59}{24}\)

\(\frac{12}{49}-\frac17=\frac{12}{49}-\frac{7}{49}=\frac{5}{49}\)

\(\frac58\times\frac{24}{25}=\frac{5\times24}{8\times25}=\frac{150}{200}=\frac{30}{40}\)

\(\frac{38}{21}:\frac{19}{3}=\frac{38}{21}\times\frac{3}{19}=\frac{114}{399}\)

34287 x 65 = 1224655

557130 : 42 = 13265

a . 20 x 3246 x 5

=( 20 x 5 ) x 3246

=100 x 3246

=324600

b . 346 x 53 +346 x 47

= 346x (53+ 47 )

= 346 x 100

= 34600

\(\) \(\frac12\)  tấn > 400 yến

\(\frac25\) m² < 3 000 cm²

\(\frac{7}{12}\) giờ > 40 phút

\(\frac14\) km > 250 m

\(\) \(\frac12\)  tấn > 400 yến

\(\frac25\) m² < 3 000 cm²

\(\frac{7}{12}\) giờ > 40 phút

\(\frac14\) km > 250 m

34287x65= 1224655

557130:42= 13265