Question 68889
(x^4+3)(x^4-5) 

<pre>FOIL METHOD 
Multiply F = First terms
Multiply O = Outer terms
Multiply I = Inner terms
Multiply L = Last terms

       (x^4 + 3)(x^4 - 5)          (x^4 + 3)(x^4 - 5) 
         |        |                  |             | 
         |        |                  |             |
       First    First              Outer         Outer

      (x^4 + 3)(x^4 - 5)           (x^4 + 3)(x^4 - 5) 
             |   |                        |        |
             |   |                        |        |
             Inner                       Last     Last
             

 
{{{x^4 (x^4) + x^4(-5)+ 3(x^4) + 3(-5)}}}

{{{x^8 - 5x^4 + 3x^4 - 15}}}        Simplify

{{{x^8 - 2x^4 - 15}}}               Combine like term



{{{(-2x-3)^2}}}
      |    | 
    base  Exponent

exponent indicates how many times you will multiply the base.

(-2x - 3)(-2x - 3)
Use FOIL Method
-2x(-2x) + (-2x)(-3) + (-3)(-2x) + (-3)(-3)
{{{4x^2 + 6x + 6x + 9}}}
Answer:
{{{4x^2 +12x + 9}}}