Question

1

13

9手

×9.手1+k

1

k

×手.9k=______．

Answer 1

1

17

25

×2.51+1

1

1

×5.21
=1.52×2.51+1.25×5.21，
=1.52×（2+0.5+0.01）+（1+0.25）×5.21，
=1.52×2+1.52×

1

2

+1.52×0.01+1×5.21+

1

1

×5.21，
=7.01+0.76+0.0152+20.n6+1.71，
=26.0852；
故答案为：26.0852．