witch2

Verified answer

(m-n)(m+n)-6(m+2n)-27 =
= м^2 +мн-мн-н^2 - 6м-12н - 27 =
= м^2 + н^2 - 6м - 12н - 27

dimanchyck2000 (m-n)(m+n) - 6(m+2n) -27 = m²- n²- 6m - 12n-27