Arcadia Prep

Links

About Arcadia LSAT Shorthand Notation Arcadia Prep's GMAT Course Arcadia Prep's LSAT Course Arcadia Prep's SAT Course Arcadia Prep's GRE Course The Simply Brilliant GMAT App About the MCAT MCAT Physical and Biological Sciences About Arcadia Prep's MCAT Course Terms of Sale Terms of Use About Arcadia Apps

LSAT Prep

Back to Questions

(A) -9 - 4√5
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Nova Math - Problem Set S: Exponents & Roots

Collapse All Subordinate Threads

Kristie M

Replies to This Thread: 0 | ----

Posted: 01/13/2013 14:10

Hi, I'm not sure why you multiply by 2+ square root 5.

Reply to This Thread (Main Topic)

Joel Brainer

Contributor

Replies to This Thread: 0 | ----

Posted: 01/13/2013 14:28

Hi Kristie, it's so that we can take advantage of the algebraic identity: a^2 - b^2 = (a-b)(a+b), and simplify the terms of the fraction, as worked out in the explanation.

Reply to This Thread (Main Topic)

Kristie M