How do you find the roots, real and imaginary, of y=(2x-8)(x-2)-x^2+4x using the quadratic formula?

1 Answer
May 7, 2017

The roots are x=4" "or" "x=5/2

Explanation:

y=(2x-8)(x-2)-x^2+4x
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y=(2x-8)(x-2)-x(x-4)
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y=(2xxx-2xx4)(x-2)-(x-4)
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y=(2(x-4))(x-2)-(x-4)
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y=2(x-4)(x-2)-(x-4)
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y=(x-4)[2(x-2)-1]
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y=(x-4)[2x-4-1]
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y=(x-4)(2x-5)
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We will find the roots when y=0
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y=0
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rArr(x-4)(2x-5)=0
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x-4=0" "rArrx=4
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" "OR
2x-5=0rArr2x=5rArrx=5/2
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The roots are x=4" "or" "x=5/2