Question

Tính nhanh                                            

3 * 72* 8 + 4 * 6 * 12 + 2 * 16 * 12

 

Answer 1

\(3.72.8+4.6.12+2.16.12\)

\(=3.8.4.18+2.2.3.2.3.2.2+2.16.3.4\)

\(=32.3.18+32.3.3+32.3.4\)

\(=32.3.\left(18+3+4\right)\)

\(=96.25\)

\(=2400\)

Answer 2

     3 x 72 x 8 + 4 x 6 x 12 + 2 x 16 x 12

 =  3 x 8 x 4 x18 + 2 x 2 x 3 x 2 x 3 x 2 x 2 + 2 x 16 x 3 x4

 = 32 x 3 x 18 + 32 x 3 x 3 + 32 x 3 x4

= 32 x 3 x ( 18+3+4)

=96 x 25

=2400