解
(m+n)平方=10
m^2+2mn+n^2=10 ①
(m-n)平方=6
m^2-2mn+n^2=6 ②
①+②得:
2m^2+2n^2=16
∴m^2+n^2=8
①-②得:
4mn=4
∴mn=1