How to solve and why the answer is (A)

Mathematics

1 answer:

Amanda [17]3 years ago

7 0

$\dfrac{1}{2}x^2+mx=5\\
\dfrac{1}{2}x^2+mx-5=0\\\\
\Delta=m^2-4\cdot\dfrac{1}{2}\cdot(-5)=m^2+10\\
\sqrt{\Delta}=\sqrt{m^2+10}\\\\
x=\dfrac{-m\pm\sqrt{m^2+10}}{2\cdot\dfrac{1}{2}}=-m\pm\sqrt{m^2+10}$

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The attached figure shows the graph for this inequality, which represents the number of goals that the opposing team could score if the referee finished the game in the first half.