Question

What are the exact solutions of x2 + 5x + 1 = 0? (5 points)

Answer 1

Answer:

$x=\frac{-5\pm\sqrt{21} }{2}$

Step-by-step explanation:

We use the quadratic formula here which says for a quadratic equation $ax^2+bx+c=0$.

$x= \frac{-b\pm\sqrt{b^2-4ac} }{2a}$

Now in our case

$a=1\\b=5\\c=1$

so we have:

$x=\frac{-5\pm\sqrt{5^2-4(1)(1)} }{2(1)} =\frac{-5\pm\sqrt{21} }{2}$

$\boxed{x=\frac{-5\pm\sqrt{21} }{2} }$

Which are our solutions.