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28 votes
28 votes
Use the quadratic formula to solve the equation2x^2-1=11xthe solution(s) are/is x=?

User Lfagundes
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3.0k points

1 Answer

20 votes
20 votes

Answer:


\begin{gathered} x=(1)/(4)(11-\sqrt[]{129}) \\ \\ x=(1)/(4)(11+\sqrt[]{129}) \end{gathered}

Step-by-step explanation:

To solve the equation we first subtract 11x from both sides to write


2x^2-11x-1=0

Now we use the quadratic formula in which a = 2, b = -11, and c = -1


x=\frac{11\pm\sqrt[]{11^2-4(2)(-1)}}{2\cdot2}
x=\frac{11\pm\sqrt[]{11^2-4(2)(-1)}}{2\cdot2}

which gives


\begin{gathered} x=(1)/(4)(11-\sqrt[]{129}) \\ x=(1)/(4)(11+\sqrt[]{129}) \end{gathered}

which are our solutions!

User James Brady
by
3.1k points
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