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Mathematics 8 Online
OpenStudy (anonymous):

Steps for solving radical equations?

OpenStudy (anonymous):

The question I'm working with is \[\sqrt{x-3}+\sqrt{x+2}=5\]

OpenStudy (anonymous):

I need the steps

OpenStudy (anonymous):

isolate the radical square each side foil simplify square simplify/solve check IS THIS CORRECT

OpenStudy (anonymous):

these pretty much suck, because you are going to have to square twice

OpenStudy (anonymous):

1. Isolate the radical expression. 2. Square both sides of the equation: If x = y then x2 = y2. 3. Once the radical is removed, solve for the unknown. 4. Check all answers.

OpenStudy (anonymous):

you want a quick method?

OpenStudy (anonymous):

Always check back your answers because the radical/square can always hide a negative in the squaring process.

OpenStudy (anonymous):

the steps i listed were the ones i saw when going over my review key

OpenStudy (anonymous):

quick method is to look at \(\sqrt{x+2}\) and ask what would make the number inside a perfect square \(x=2\) would work because \(2+2=4\) but it won't work for \(\sqrt{x-3}\) \(x=7\) works because \(7+2=9\) so lets try that one \[\sqrt{7-3}+\sqrt{7+2}=\sqrt{4}+\sqrt{9}=2+3=5\] got it on the second guess

OpenStudy (anonymous):

i'd prefer the other way i listed if it is correct

OpenStudy (anonymous):

if you don't like the thinking method you have to write \[\sqrt{x-3}+\sqrt{x+2}=5\\ \sqrt{x-3}=5-\sqrt{x+2}\] then square both sides (carefully) and get \[x-3=25-10\sqrt{x+2}+x+2\] then combine like terms on the rigth \[x-3=27+x-10\sqrt{x+2}\] isolate the radical and get \[-30=-10\sqrt{x+2}\\ 3=\sqrt{x+2}\]

OpenStudy (anonymous):

now square again and get \[9=x+2\] and so \(x=7\) but really this is long an involved i know most people, especially math teachers, like "step step step..." but it never hurts to think first maybe you get it right away

OpenStudy (anonymous):

i have to show all rhe work that is the only issue

OpenStudy (anonymous):

i guess you can't show "thinking" any decent math teacher would be pleased at finding an answer from dint of sheer brain power, but whatever all steps are above

OpenStudy (anonymous):

thank you

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