Question

tính nhanh 

a ) 2x31x12+4x6x42+8x27x3

b) 36x38+36x82+64x69+64x41

Answer 1

a, \(2.31.12+4.6.42+8.27.3=24.31+24.42+24.27=24.\left(31+42+27\right)=31.100=3100\)

b, \(36.38+36.82+64.69+64.41=36.120+64.110=11360\)

Answer 2

a)       \(2.31.12+4.6.42+8.27.3\)

\(=\)\(\left(2.12\right).31+\left(4.6\right).42+\left(8.3\right).27\)

\(=\)\(24.31+24.42+24.27\)

\(=\)\(24.\left(31+42+27\right)\)

\(=\)\(24.100\)

\(=\)\(2400\)

Answer 3

      \(36.38+36.82+64.69+64.41\)

\(=\)\(36.\left(38+82\right)+64.\left(69+41\right)\)

\(=\)\(36.120\)             \(+64.110\)

\(=\)\(4320\)                 \(+7040\)

\(=\)\(11360\)