document.write( "Question 448525: Find the X-intercepts of a parabola with the vertex at (-3,16) and the Y-intercept at (0,-20) \n" ); document.write( "
Algebra.Com's Answer #308623 by ewatrrr(24785)\"\" \"About 
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document.write( "Find the X-intercepts of a parabola with the vertex at (-3,16)
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document.write( "and the Y-intercept at  (0,-20)
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document.write( "Using the vertex form of a parabola, \"y=a%28x-h%29%5E2+%2Bk\" where(h,k) is the vertex
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document.write( "  y = a(x+3)^2 +16
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document.write( " -20 = a * 9 + 16
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document.write( " -36 = 9a
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document.write( "  -4 = a
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document.write( "  y = -4(x+3)^2 +16
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document.write( "x-intercepts when y = 0
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document.write( " -4(x+3)^2 = -16
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document.write( "   (x+3)^2 = 4
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document.write( "    x+3 = ± 2
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document.write( "    x = -3 ± 2   x = -5  and x = -1\r
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