数学问题，求解

Question

m^2+n^2=10
mn=3
m+n=??

Answer 1

(m+n)²
=m²+n²+2mn
=10+2*3
=16
所以m+n=4或-4

Answer 2

m^2+n^2+2mn=10+2*3=16

(m+n)^2=16
m+n=4或m+n=-4本回答被提问者采纳

Answer 3

Answer 4

（m+n）2=m2+n2+2mn=16，m+n=4或-4