已知(m²+n²+2)²=9 则2m²+2n²为?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/05 06:39:36
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已知(m²+n²+2)²=9 则2m²+2n²为?
已知(m²+n²+2)²=9 则2m²+2n²为?
已知(m²+n²+2)²=9 则2m²+2n²为?
∵(m²+n²+2)²=9,且m²+n²≥0
∴m²+n²+2=3即m²+n²=1
∴2m²+2n²=2
(m²+n²+2)²=9
m²+n²+2=±3
m²+n²=-5 或1
2m²+2n²=2(m²+n²)=-10或2