document.write( "Question 389427: Find the x-intercepts of the parabola with vertex (-5,80) and y-intercept (0,-45). \n" ); document.write( "

Algebra.Com's Answer #275952 by ewatrrr(24785) $\"\"$ $\"About$

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document.write( "Hi,  
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document.write( "the vertex form of a parabola,  where(h,k) is the vertex
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document.write( "vertex (-5,80)
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document.write( "y =a(x+5)^2 + 80
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document.write( "using y-intercept pt(0,45) to find a
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document.write( "45 = a(5)^2 + 80
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document.write( "-35 = a*25
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document.write( " -35/25 = a
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document.write( "y = -7/5(x+5)^2 +80  OR y = -7/5[x^2 +10x + 25] + 80
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document.write( "finding x-intercepts  (y = 0)
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document.write( "-7/5[x^2 +10x + 25] + 80 = 0
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document.write( " -7/5x^2 - 14x -35 + 80 = 0
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document.write( " -7/5x^2 - 14x +45 = 0
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