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Algebra help! please!

I have an algebra problem and the answer I just need to know the steps involved. 4 - the square root of -20 divided by 2. The answer is 2 minus i the square root of 5.

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Mrs.RockStar

Asked by Mrs.RockStar at 10:56 PM on Jun. 18, 2009 in Money & Work

Level 1 (0 Credits)
Answers (4)
  • This looks like arithmetic, not algebra; you should be able to do this on your calculator.
    This is one of the websites my daughter used in 7th grade to help her with HS honors algebra: http://mathforum.org/dr.math/
    rkoloms

    Answer by rkoloms at 5:45 AM on Jun. 19, 2009

  • Wish I could help, but I'm a complete math idiot! Good Luck though!
    rune2319

    Answer by rune2319 at 8:47 AM on Jun. 19, 2009

  • okay...this is intermediate level algebra. Is the whole "4-sqrt(20)" divided by 2?
    michiganmom116

    Answer by michiganmom116 at 11:25 AM on Jun. 19, 2009

  • The rule is that you do exponents and squares before you do multiplication and division. Then you do addition and subtraction last. So unless there were parenthesis in the problem, do the square root of negative 20 first. which according to my calculator is 4.4721 i (I think I have this set to only give 4 digits)


    Oh wait, I see by your answer that 4 minus the square root of negative 20 is your numerator and that entire thing is divided by 2 (the denominator) and you don't care about converting the square root to a decimal.


    Okay the square root of negative 20 is the same thing as (the square root of negative one) x the square root of 4 x the square root of 5. So that part comes out 2i times square root of 5. So 4-2i times the square root of 5 all gets divided by 2. The 4 becomes 2. The 2i becomes one i. And you have your answer as given. If you need anymore help let me know.

    LoveMyDog

    Answer by LoveMyDog at 2:07 PM on Jun. 19, 2009

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