Use the FOIL method to find the trinomial.
FOIL - First, Outer, Inner, Last
(Bolded terms are the terms being multiplied.)
First
(4x + 5)(9x + 9)
[tex]4x * 9x = 36x^{2}[/tex]
Outer
(4x + 5)(9x + 9)
[tex]4x * 9 = 36x[/tex]
Inner
(4x + 5)(9x + 9)
[tex]5 * 9x = 45x[/tex]
Last
(4x + 5)(9x + 9)
[tex]5 * 9 = 45[/tex]
Add all of these results together:
[tex]36x^{2} + 36x + 45x + 45[/tex]
Simplify by combining like terms.
[tex]36x^{2} + 81x + 45[/tex]
The answer is D. 36x^2 + 81x + 45.
