若m+n=3,则2m²+4mn+2n²-6的值为( ) A.12 B.6 C.3 D.0
来源:学生作业学帮网 编辑:学帮网 时间:2024/05/30 18:54:51
若m+n=3,则2m²+4mn+2n²-6的值为( ) A.12 B.6 C.3 D.0
m+n=3
2m²+4mn+2n²-6
=2(m²+2mn+n²)-6
=2(m+n)²-6
=18-6
=12
2m²+4mn+2n²-6
=2(m+n)^2-6
=2x9-6
=12
收录互联网各类作业题目,免费共享学生作业习题
慧海网手机作业共收录了 千万级 学生作业题目
来源:学生作业学帮网 编辑:学帮网 时间:2024/05/30 18:54:51
若m+n=3,则2m²+4mn+2n²-6的值为( ) A.12 B.6 C.3 D.0
m+n=3
2m²+4mn+2n²-6
=2(m²+2mn+n²)-6
=2(m+n)²-6
=18-6
=12
2m²+4mn+2n²-6
=2(m+n)^2-6
=2x9-6
=12