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Explanation:
I'm assuming you meant to write $10,600 instead of $10,6000.
We'll replace y with this value and solve for x.
[tex]y=10,000+50x-x^2\\\\10,600=10,000+50x-x^2\\\\0=10,000+50x-x^2-10,600\\\\-x^2+50x-600 = 0[/tex]
Use the quadratic formula with a = -1, b = 50, c = -600
[tex]x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}\\\\x = \frac{-50\pm\sqrt{(50)^2-4(-1)(-600)}}{2(-1)}\\\\x = \frac{-50\pm\sqrt{100}}{-2}\\\\x = \frac{-50\pm10}{-2}\\\\x = \frac{-50+10}{-2} \ \text{ or } \ x = \frac{-50-10}{-2}\\\\x = \frac{-40}{-2} \ \text{ or } \ x = \frac{-60}{-2}\\\\x = 20 \ \text{ or } \ x = 30\\\\[/tex]
We go for the smaller x value because the question asks "what is the least amount she can raise the price?".
If she raises the price by $20, then she would estimate to make about $10,600.