Answer:
2mn
Explanation:
The expanded form of the square can be found using the distributive property.
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(m -n)² = (m -n)(m -n) = m(m -n) -n(m -n) . . . use the distributive property
= m² -mn -nm +n² . . . . use it again
= m² -2mn +n² . . . . . . combine like terms
The missing term is 2mn.