SOLUTION: solve the following quadratic equation by factoring 15x^3-4x^2-4x=0

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Question 78619: solve the following quadratic equation by factoring
15x^3-4x^2-4x=0
Answer by chitra(359) About Me  (Show Source):
You can put this solution on YOUR website!
The given expression is:

15x%5E3+-+4x%5E2+-+4x+=+0+

15x%5E3+-+10x%5E2+%2B+6x%5E2+-+4x+=+0+

+5x%5E2%283x+-+2%29+%2B+2x%283x+-+2%29+=+0+


%285x%5E2+%2B+2x%29%283x+-+2%29=+0+

==> %285x%5E2+%2B+2x%29+=+0+ or 3x - 2 = 0

==> x(5x + 2) = 0 or (3x - 2) = 0

==> x = 0 or (5x + 2) = 0 or 3x = 2

==> x = 0 or 5x = -2 or x = 2/3

==> x = 0 or x = -5/2 or x = 2/3


Since the given polynomial is a cubic polynomial we get 3 roots and the roots are:

x = 0, x = -5/2, x = 2/3

Hence, the solution.