KEVIN B.

asked • 11/18/13

what is the product. ( x-9)(x+8)

Find  the product. (X-9)(x+8)

2 Answers By Expert Tutors

By:

Jason S. answered • 11/18/13

Tutor
4.9 (116)

My goal is the success of my students. Knowledge-Patience-Honesty

KEVIN B.

Thank you Jason I really appreciate it  
Report

11/18/13

Parviz F.

I just think  this the FILE method is very useless formula to memorize , and confuse.
 
  The method  that I gave  has application  in factoring quadratic , Trinomial to product of  2 binomial.
 
    ( X + a) ( X +b ) = X2 +( a + b) X + ab
  
      Which is used in solution of quadratic equations, and when a quadratic is favorable, and when it has irrational and complex roots.
Report

11/18/13

Jason S.

You are most welcome Kevin.
 
Parviz,
 
FOIL is extremely effective, in my years of experience, in helping students to remember why the following works:
 
(ax + b) (cx + d) = (ac)x^2 + (ad)x + (bc)x + bd = 
 
 
(ac)x^2 + (ad+bc)x + bd

ac is first
ad is outside
bc is inside
bd = outside
 
The words make much more sense to the students than the complicated formula, in my experience.
Report

11/19/13

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.