Question

3.7×4.9-3.9×4.7的简便运算

Answer 1

简便运算方法过程如下
3.7x4.9-3.9x4.7
=3.7x4.9-(3.7+0.2)x4.7
=3.7x4.9-3.7x4.7-0.2x4.7
=3.7x(4.9-4.7)-0.2x4.7
=3.7x0.2-0.2x4.7
=0.2x(3.7-4.7)
=0.2x(-1)
=-0.2
希望可以帮到你

Answer 2

3.7*4.9-3.9*4.7=
(4-0.3)(5-0.1)-(4-0.1)(5-0.3)=
20-0.4-1.5+0.03-20+1.2+0.5-0.03=
0.1-0.3=-0.2

Answer 3

3.7×4.9-3.9×4.7
=（4.7-1）×4.9-3.9×4.7
=4.7×4.9-1×4.9-3.9×4.7
=4.7×（4.9-3.9）-4.9
=4.7×1-4.9
=4.7-4.9
=-0.2
希望能帮到你！