问题 填空题

7.2×1.69+3.14×2.8+1.45×7.2=______.

答案

7.2×1.69+3.14×2.8+1.45×7.2

=(1.69+1.45)×7.2+3.14×2.8,

=3.14×7.2+3.14×2.8,

=(7.2+2.8)×3.14,

=10×3.14,

=31.4.

故答案为:31.4.

单项选择题
单项选择题