Упростите выражение (a-9)^2-(81+2a).

Question

\[(a - 9)^{2} - (81 + 2a) =\]

\[= a^{2} - 18a + 81 - 81 - 2a =\]

\[\ = a^{2} - 20a\]

Accepted Answer

\[(a - 9)^{2} - (81 + 2a) =\]

\[= a^{2} - 18a + 81 - 81 - 2a =\]

\[\ = a^{2} - 20a\]

Ответ: