Mathematics
10 Online
OpenStudy (anonymous):
x-2= square root2x-5 solve equation???
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Parth (parthkohli):
Can you find the square of both sides?
Parth (parthkohli):
\( \color{Black}{\Rightarrow (x - 2)^2 = \sqrt{2x - 5}^2}\)
Parth (parthkohli):
Remember:
\((a - b)^2 = a^2 - 2ab + b^2\)
OpenStudy (anonymous):
(a-b)^2 = a^2 - 2ab + b^2
OpenStudy (anonymous):
2x-5=x^2-4x+4
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Parth (parthkohli):
That's right.
Now add 5 to both sides, then subtract 2x from both.
Parth (parthkohli):
You'd supposedly have a quadratic equation after doing all that.
OpenStudy (theviper):
Square both sides :)
OpenStudy (anonymous):
x^2-6x +9
Parth (parthkohli):
That's right!
You may use factoring, as that is a perfect square.
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Parth (parthkohli):
Factoring/completing the square.
OpenStudy (anonymous):
answer would be (-3,3)
Parth (parthkohli):
Nope, there's only one root here with a multiplicity of 2(remember how we have an exponent of 2?)
Parth (parthkohli):
You may express \(x^2 - 6x + 9\) as a perfect square. How'd you do that?
OpenStudy (anonymous):
(x-3)(x+3)
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Parth (parthkohli):
Nope. That makes \(x^2 - 9\) when you multiply 'em out.
Parth (parthkohli):
And that's not a perfect square..
OpenStudy (anonymous):
your right.
OpenStudy (anonymous):
(x-3)(x-3)
OpenStudy (anonymous):
so x=3
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Parth (parthkohli):
Yep, so what's the solution?
OpenStudy (anonymous):
x=3
Parth (parthkohli):
That's correct!