28×42十29×56用简便方法计算

Question

28×42十29×56用简便方法计算

Answer 1

28×42十29×56
=28×42十(28+1)×56
=28×42+28×56+56
=28×(42+56)+56
=28×(100-2)+56
=2800-56+56
=2800本回答被网友采纳

Answer 2

28×42十29×56
=28x(42+29x2)
=28x100
=2800

Answer 3

28*42+（28*2）*29=28*（42+58）=28*100=2800