Sender: "Pat"
Date: Mon, 17 May 1999 11:13:39 -0700

Level: Introductory Algebra
Person asking question: Student

(2 + sq. root of 3) x (2 - sq. root of 3) = 1

Please show me the work.

Thank you.
PAT

Hi Pat
There are two ways to approach this problem. You can expand the left side using the distributive law or you can expand the left side by recognizing a pattern. A large part of algebra is recognizing patterns.
   If you don't see the pattern then use the distributive law

The pattern that you might have recognized is the difference of squares which says that for any numbers a and b,

a2 - b2 = (a - b)(a + b)

You can prove that this expression is true by expanding the right side as above. If you recognize

as the right side of the difference of squares expression with a = 2 and b =  then you see immediately that

Cheers,
Harley

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