Question

3. (03.07)
Which of the following is a solution of x2 + 5x = -2? (2 points)
O 5 + 733
2
O 5 =√17
2
O -5+133
2
O -5=17
2.

Answer 1

Answer:

${x}^{2} + 5x = - 2$

arrange the equation according to general formula;

General formula: ax² + bx + c = 0

therefore:

${x}^{2} + 5x + 2 = 0$

Using the quadratic equation :

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

a » 1, b » 5, c » 2

substitute:

$x = \frac{ - 5± \sqrt{ {5}^{2} - (4 \times 1 \times 2) } }{(2 \times 1)} \\ \\ x = \frac{ - 5± \sqrt{17} }{2}$

therefore solutions are;

${ \boxed{ \boxed{x_{1} = \frac{ - 5 + \sqrt{17} }{2} }}} \: \: and \: \: { \boxed{ \boxed{x_{2} = \frac{ - 5 - \sqrt{17} }{2} }}}$

x is -0.438 and -4.562