Question 293591
{{{8x^3+4x^2-18x-9=0}}}
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Group terms:
{{{(8x^3+4x^2)-(18x+9)=0}}}
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{{{4x^2(2x+1)-9(2x+1)=0}}}
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{{{(2x+1)(4x^2-9)=0}}}
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Set each term to zero:
2x+1 = 0
2x = -1
x = -1/2
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4x^2-9 = 0
4x^2 = 9
x^2 = 9/4
x = +- 3/2
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x = {-3/2, -1/2, 3/2}