Solving 4√(x-2) + 8 = 3√(x+6) - 5 for x

  • Thread starter Thread starter DB
  • Start date Start date
  • Tags Tags
    System
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 3K views
DB
Messages
501
Reaction score
0
my teacher showed me how to solve this but she said we don't have to know it till cegep. id still like to know how to do it, can u guys help me refresh my memory?

[tex]-4\sqrt{x-2} + 8=3\sqrt{x+6}-5[/tex]

solve for x
 
Physics news on Phys.org
You can solve these kind of irrational equations by squaring both sides, it may be necessary to do so more than once.
You square because you want to get rid off the square roots, so it's necessary to carefully choose what to put on what side because you don't want to create new square roots as a result of mixed terms, or at least you want to minimize the number of those.

You have to be careful though, when squaring - the sign of both sides has to be the same and all expressions under the square roots can't be negative, these constraints give you conditions to test on your final answers - some may have to be cancelled.