177 097          70 079                        15 445                        321

152 399 + 24 457 = 176 856

6992 508 – 22 384 = 6 970 124

429 089 x 5 = 2 145 445

143 263 : 9 = 15 918 dư 1

267 + 731 = 998

328 + 56 = 384

698 - 47 = 651

721 - 350 = 371

\(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{267}\\{731}\end{array}}\\\hline{\,\,\,\,998}\end{array}\)                               \(\begin{array}{*{20}{c}}{ + \begin{array}{*{20}{c}}{328}\\{\,\,56}\end{array}}\\\hline{\,\,\,384}\end{array}\)

\(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{698}\\{\,\,47}\end{array}}\\\hline{\,\,\,651}\end{array}\)                               \(\begin{array}{*{20}{c}}{ - \begin{array}{*{20}{c}}{721}\\{350}\end{array}}\\\hline{\,\,\,371}\end{array}\)

1)   \(152\times9+152\times1=152\times\left(9+1\right)=152\times10=1520\)

2)    \(24\times999+24\times1=24\times\left(999+1\right)=24\times1000=24000\)

1/ 152 x 9 + 152 x 1 = 152 x ( 9 + 1 ) = 152 x 10 = 1520

2/ 24 x 999 + 24 x 1 = 24 x ( 999 + 1 ) = 24 x 1000 = 24000

\(\frac{254+399.253}{399.254-145}\)

\(=\frac{254+399.253}{399.\left(253+1\right)-145}\)

\(=\frac{254+399.253}{399.253+399.1-145}\)

\(=\frac{254+1}{1+399-145}=1\)

Chúc bạn học tốt!!!

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