Question

Solve the equation x^2 + 5x = -1 by completing the square.

Answer 1

Answer:

The answer to your question is: the third option

Step-by-step explanation:

              x² + 5x = - 1

              x² + 5x + $(\frac{5}{2}) ^{2}$ = -1  + $(\frac{5}{2} )^{2}$

             (x + $\frac{5}{2}$)² =   - 1 + 25/4

            (x + $\frac{5}{2}$)²  =  (-4 + 25) / 4

            (x + $\frac{5}{2}$)² = 21/4

            (x + $\frac{5}{2}$) = ± $\sqrt{\frac{21}{4} }$

            x = $\frac{5}{2} ± \frac{\sqrt{21}}{2}$

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