Question 523000
You need to specify your problem completely.  What you have provided is only an expression, which technically cannot be solved, it can only be simplified.  You need an equation to solve.
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Assuming your equation is:
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{{{ y = (6-8x^2)/(4+5)  }}}
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{{{ 9y = 6 -8x^2 }}}
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{{{ 9y = -8x^2 + 6 }}}
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{{{ y = -(8/9)x^2 + 6/9 }}}
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{{{ y = -(8/9)x^2 + 2/3 }}}
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{{{ graph(500,500,-2,2,-2,2,-8/9*x^2+2/3) }}}
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To find the zeroes (roots), set y = 0.
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{{{ 0 = -(8/9)x^2 + 2/3 }}}
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{{{ (8/9)x^2 = 2/3 }}}
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{{{ 8x^2 = 2/3*9 = 6 }}}
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{{{ x^2 = 6/8 = 3/4 }}}
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{{{ x = sqrt(3/4) = sqrt(3)/2 }}}
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x = -.866 or .866