2. Tính theo 2 cách: 540 x 9 + 480 x 9 476 : ( 17 x4 )

#andy

\[\begin{array}{l}
a)\\
540 \times 9 + 480 \times 9\\
C1:540 \times 9 + 480 \times 9\\
 = 4860 + 4320\\
 = 9180\\
C2:540 \times 9 + 480 \times 9\\
 = \left( {540 + 480} \right) \times 9\\
 = 1020 \times 9\\
 = 9180\\
b)\\
476:\left( {17 \times 4} \right)\\
C1:476:\left( {17 \times 4} \right)\\
 = 476:68\\
 = 7\\
C2:476:\left( {17 \times 4} \right)\\
 = 476:17:4\\
 = 28:4\\
 = 7
\end{array}\]