简便计算.1.2.6*0.25+7.4除以4= 2.89.3*43+3.8*893+8.93*190= 3.0.7777*0.7+0.1111*2.1=

1.2.6x0.25+7.4÷4
=2.6x0.25+7.4x0.25
=(2.6+7.4)x0.25
=10x0.25
=2.5
2.89.3x43+3.8x893+8.93x190
=8.93x430+8.93x380+8.93x190
=8.93x(430+380+190)
=8.93x1000
=8930
3.0.7777*0.7+0.1111*2.1
=0.7777x0.7+0.7777x0.3
=0.7777x(0.7+0.3)
=0.7777x1
=0.7777