Question

这道题应该怎么做？

Answer 1

显然，x≠0且y≠0

x*√(y/x) +y*√(x/y)

=√(x² *y/x) +√(y² *x/y)

=√xy +√xy

=2√xy 

=2√8

=4√2 

Answer 2

x√y/x+y√x/y
=x√y/√x+y√x/√y
=x·√y·√y/√x√y+y·√x·√x/√x√y
=xy/√xy+xy/√xy
=2xy/√xy
=2xy·√xy/√xy·√xy
=2xy·√xy/xy
=2√xy
因为xy=8
所以2√xy=2√8=4√2