已知ab=1,2a+b=3,则式子b/2a+2a/b=

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已知ab=1,2a+b=3,则式子b/2a+2a/b=已知ab=1,2a+b=3,则式子b/2a+2a/b=已知ab=1,2a+b=3,则式子b/2a+2a/b=b/2a+2a/b=(b²+

已知ab=1,2a+b=3,则式子b/2a+2a/b=
已知ab=1,2a+b=3,则式子b/2a+2a/b=

已知ab=1,2a+b=3,则式子b/2a+2a/b=
b/2a+2a/b
=(b²+4a²)/2ab
=[(b+2a)²-4ab]/2ab
=(3²-4x1)/2x1
=(9-4)/2
=2.5

2a+b=3 平方一下
4a^2+4ab+b^2=9
4a^2+b^2=9-4ab=9-4=5

b/2a+2a/b
=(b^2+4a^2)/2ab
=5/2