非常急..【1、填空】8.8×7.5=8×【 】×【 】×2.5=﹙【 】×【 】﹚×﹙8×2.5﹚7.9×2.1+7.
5个回答

8.8×7.5=8×【1.1 】×【 3 】×2.5=﹙【 1.1 】×【3 】﹚×﹙8×2.5﹚

7.9×2.1+7.9×7.9=【 7.9 】×﹙【2.1 】+【 7.9 】﹚

2.5×﹙2.83×0.4﹚=﹙【 2.5 】×【 0.4 】﹚×【 2.83 】

25×6.7-25×2.7

=25×﹙6.7-2.7﹚

=25×4

=100

3.7×2.3+2.3×6.3

=2.3×﹙3.7+6.3﹚

=2.3×10

=23

99×3.5+3.5

=3.5×﹙99+1﹚

=3.5×100

=350.