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How many real-number solutions does the quadratic equation 2x^2 + 7x + 9 = 0 have?

User WindowsMaker
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1 Answer

15 votes
15 votes

We are given the following equations:


2x^2+7x+9=0

This is an equation of the form:


ax^2+bx+c=0

To determine the number and type of solutions we can use the discriminant of the equation. The discriminant is determined by the following number:


\Delta=b^2-4ac

Now, we plug in the values:


\Delta=(7)^2-4(2)(9)

Now, we solve the operations:


\Delta=-23

The number and type of solutions are given by the following conditions:


\begin{gathered} \Delta>0,\text{ two real solutions} \\ \Delta=0,\text{ one real solutions} \\ \Delta=\text{ two complex solutions} \end{gathered}

Since we get that:


\Delta=-23<0

Therefore, the equation has two complex solutions and therefore, no real number solution.

User Andrew Sawa
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