expand. your answer should be a polynomial in standard form. (9 + m)(-m + 9) =

Explanation:

Step1: Use FOIL method

$(9 + m)(-m + 9)=9\times(-m)+9\times9+m\times(-m)+m\times9$

Step2: Calculate each product

$9\times(-m)=-9m$, $9\times9 = 81$, $m\times(-m)=-m^{2}$, $m\times9 = 9m$

Step3: Combine like - terms

$-9m+9m - m^{2}+81=-m^{2}+( - 9m + 9m)+81=-m^{2}+81$

Answer:

$-m^{2}+81$