1/a+1/b=1/(a+b) 求b/a+a/b的值

1/a+1/b=1/(a+b)so (a+b)/ab=(a+b)即（a+b）^2=aba^2+b^2=-abb/a+a/b=(b^2+a^2)/ab=-12.(2a)/(a²－4) ＋1/( 2－a)=2a/[(a+2)(a-2)]-1/(a-2)=(2a)/[(a+2)(a-2)]-(a+2)/[(a+2)(a-2)]=1/(a+2)=1/(1/2+2)=2/53.(x＋...