Question 258619
write the expression in expanded standard polynomial form. 
1. (x-9)^2
= (x-9)(x-9) = x(x-9)-9(x-9)
= x^2-9x-9x+81
= x^2 -18x+81
-------------------------
2. (x+5)(x-4)
= x(x-4)+5(x-4) 
= x^2-4x+5x-20
= x^2 -9x -20
------------------------- 
Then for the other two that I'm having a hard time with, I'm supposed to put the polynomials in factored form where possible. 
1. m^2+9
Unless you have studied complex numbers this expression is not factorable.
----------------------------------------
2. m^2-12m+36
= m^2 - 6m - 6m + 36
= m(m-6)-6(m-6)
= (m-6)(m-6)
--------------------------------- 
Cheers,
Stan H.