Question

用简便方法运算 1题.2015的平方 2题 1.234的平方＋0.766的平方+2

Answer 1

1. 2015^2

=(2000+15)^2

=4000000+60000+225

=4060225

2. 1.234^2+0.766^2+2.468*0.766

=(1.234+0.766)^2

=2^2

=4