Answer:
mn = 4
Step-by-step explanation:
(m+n)^2 = m^2 + 2mn + n^2
(m-n)^2 = m^2 - 2mn + n^2 multply the second equation by (-1) then subtract it from first equation
m^2 + 2mn + n^2 - m^2 + 2mn - n^2 = 16
4mn = 16 divide both sides by 4
