问题 填空题
化简:
121×0.81
=______;
52+122
=______,
412-402
=______.
答案

121×0.81

=

121
×
0.81

=11×0.9=9.9;

52+122

=

25+144

=

169

=13;

412-402

=

(41+40)×(41-40)

=

81

=9.

故答案为:9.9;13;9.

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