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

`{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 * 1 * 2) } }{(2 * 1)} \\ \\ x = ( - 5± √(17) )/(2)`

therefore solutions are;

`{ \boxed{ \boxed{x_(1) = ( - 5 + √(17) )/(2) }}} \: \: and \: \: { \boxed{ \boxed{x_(2) = ( - 5 - √(17) )/(2) }}}`

x is -0.438 and -4.562