若ab=-1,a+b=2,则式子b/a+a/b=()

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若ab=-1,a+b=2,则式子b/a+a/b=()
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若ab=-1,a+b=2,则式子b/a+a/b=()
若ab=-1,a+b=2,则式子b/a+a/b=()

若ab=-1,a+b=2,则式子b/a+a/b=()
b/a+a/b
=(b²+a²)/ab
=-(a²+b²)
=-(a+b)²+2ab
=-(2)²+2(-1)
=-4-2
=-6

b/a+a/b=(a^2+b^2)/ab=[(a+b)^2-2ab]/(ab)=[4+2]/(-1)=-6

b/a+a/b=ab(b/a+a/b)/ab
=(b^2+a^2)/ab
=(a^2+2ab+b^2-2ab)/ab
=((a+b)^2-2ab)/ab 把ab=-1,a+b=2代入
=(2*2-2*(-1))/(-1)
=-6

b/a+a/b
=(b²+a²)/ab
=[(a+b)2-2ab]/ab
=[22-2x(-1)]/-1
=-6