x+y=(x+y)*1
=(x+y)*(a/x+b/y)
=a+b+ay/x+bx/y
=10+(ay/x+bx/y)
≥10+2√[ay/x*bx/y]
=10+2√(ab)
所以10+2√(ab)=18→ab=16
a+b=10
联立求出a,b:a=2,b=8或者a=8,b=2
x+y=(x+y)*1
=(x+y)*(a/x+b/y)
=a+b+ay/x+bx/y
=10+(ay/x+bx/y)
≥10+2√[ay/x*bx/y]
=10+2√(ab)
所以10+2√(ab)=18→ab=16
a+b=10
联立求出a,b:a=2,b=8或者a=8,b=2