用简便方法(结果用科学计数法表示)
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/05/10 05:49:12
用简便方法(结果用科学计数法表示)
49.9^2+9.98+0.1^2 99^2+199
49.9^2+9.98+0.1^2 99^2+199
49.9^2+9.98+0.1^2
=49.9^2+2x0.1x44.9+0.1^2
=(49.9+0.1)²
=50²
=2500
=2.5x10^3
99^2+199
= 99^2+198+1
=99^2+2x99+1^2
=(99+1)²
=100²
=10000
=1x10^4
=49.9^2+2x0.1x44.9+0.1^2
=(49.9+0.1)²
=50²
=2500
=2.5x10^3
99^2+199
= 99^2+198+1
=99^2+2x99+1^2
=(99+1)²
=100²
=10000
=1x10^4