Question

Tính nhanh: 58.42+32.58+74.42

 

Answer 1

        \(58.42+32.58+74.42\)

\(=58\left(32+42\right)+74.42\)

\(=58.74+74.42\)

\(=74\left(58+42\right)\)

\(=74.100\)

\(=7400\)

Answer 2

58 x 42 + 32 x 58 + 74 x 42

= 58 x 42 + 58 x 32 + 74 x 42

= 58 x ( 42 + 32 ) + 74 x 42

= 58 x 74 + 74 x 42

= 58 x 74 + 42 x 74

= ( 58 + 42 ) x 74

= 100 x 74

= 7400