FOIL QUESTION

Question

FOIL: (4X+3)(5X-3_

Answer 1

(4X+3)(5X-3)

 

      First                    Outside                    Inside                Last

   4x(5x)       +           4x(-3)         +          3(5x)        +      3(-3)

     20x^2w        -          12x              +           15x          -         9

     20x²         +                        3x                              -   9

 

  20x² + 3x - 9

Answer 2

Multiply each term in the first set of parentheses by each term in the second set of parentheses. 

 

Start with 4x times 5x.  Break it down further if you need to: 4 times 5 times x times x.  Should be 20 times x squared, or just 20x². Keep doing this multiplying with all the terms.  

 

Then combine or add/subtract like terms - terms that have the same variable and same exponent.  

 

I will add that this is really exactly like the old-fashioned procedure for multiplying two 2-digit numbers, where you had to multiply each digit by every digit in the other number.