减去4a等于3a^2-2a-1的整式是( ) a.3a^2-6a-1 b.5a-1 c.3a^2+2a-1 d.3a^2+6a-1

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/28 13:27:13
减去4a等于3a^2-2a-1的整式是( ) a.3a^2-6a-1 b.5a-1 c.3a^2+2a-1 d.3a^2+6a-1

减去4a等于3a^2-2a-1的整式是( ) a.3a^2-6a-1 b.5a-1 c.3a^2+2a-1 d.3a^2+6a-1
减去4a等于3a^2-2a-1的整式是( ) a.3a^2-6a-1 b.5a-1 c.3a^2+2a-1 d.3a^2+6a-1

减去4a等于3a^2-2a-1的整式是( ) a.3a^2-6a-1 b.5a-1 c.3a^2+2a-1 d.3a^2+6a-1
根据“被减数=差+减数”
得:
减去4a等于3a^2-2a-1的整式
=4a+3a^2-2a-1
=2a+3a^2-1
=3a^2+2a-1
选择 C
江苏吴云超解答 供参考!

三人体重:小张x、小王y、小李z
x+z=98.8
y+z=86.5
两式相减
x-y=98.8-86.5=12.3
小张比小王重12.3千克