SOLUTION: Working backwards write a quadratic equation that will have solutions of x = 3 and x = -7. Working backwards write a quadratic equation that will have solutions of x = 12 and x

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: Working backwards write a quadratic equation that will have solutions of x = 3 and x = -7. Working backwards write a quadratic equation that will have solutions of x = 12 and x       Log On


   

Question 1156900: Working backwards write a quadratic equation that will have solutions of x = 3 and x = -7.
Working backwards write a quadratic equation that will have solutions of x = 12 and x = 2.
Thank you
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Note that if +x+=+3+, then +x+-+3+=+0+,
and +x+=+3+ is a root of the quadratic
+f%28x%29+=+%28+x+-+3+%29%2A%28+x+-%28-7%29+%29+
+f%28x%29+=+%28+x+-+3+%29%2A%28+x+%2B+7+%29+
+f%28x%29+=+x%5E2+-+3x+%2B+7x+-+21+
+f%28x%29+=+x%5E2+%2B+4x+-+21+
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check:
+x+=+3+
+f%283%29+=+3%5E2+%2B+4%2A3+-+21+
+f%283%29+=+9+%2B+12+-+21+
+f%283%29+=+0+
You can check ( x = -7 )
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+f%28x%29+=+%28+x+-+12+%29%2A%28+x+-+2+%29+
Multiply this out and follow the 1st answer