Answer :
Answer:
x = 1, -5.56
Step-by-step explanation:
x^2 = -7x - 8
shift -7x and -8 to the other side . Remember when u shift minus changes into plus.
x^2 + 7x + 8 = 0
using quadratic equation formula
in quadratic equation one value comes positive and other comes in negative
a = 1 , b = 7 and c = 8
taking positive sign
x = (-b + [tex]\sqrt{b^2 - 4*a*c}[/tex]) /2*a
x = (-7 + [tex]\sqrt{7^2 - 4*1*8}[/tex] ) /2*1
x = (-7 + [tex]\sqrt{49 + 32}[/tex] ) /2
x = (-7 + [tex]\sqrt{81}[/tex] )/ 2
x = -7 + 9 / 2
x = 2/2
x = 1
taking negative sign
(-b - [tex]\sqrt{b^2 - 4*a*c}[/tex] ) /2*a
x = (-7 - [tex]\sqrt{7^2 - 4*1*8}[/tex] ) /2*1
x = (-7 - [tex]\sqrt{49 - 32}[/tex] ) /2
x = -7 - [tex]\sqrt{17}[/tex] / 2
x = -7 - 4.12 / 2
x = -11.12/2
x = -5.56
therefore x = 1 , - 5.56
Answer:
[tex]x = \frac{- 7 + \sqrt{17}}{2} \ , \ x = \frac{-7 - \sqrt{17}}{2}[/tex]
Step-by-step explanation:
[tex]x^2 = - 7x - 8\\\\x^2 + 7x + 8 = 0 \\\\[/tex]
[tex]x = \frac{- b \pm \sqrt{b^2 - 4ac}}{2a}\\\\[/tex] [tex][ \ a = 1 , \ b = 7 , \ c = 8 \ ][/tex]
[tex]x = \frac{-7 \pm \sqrt{49 - (4\times 8)}}{2} \\\\x = \frac{-7 \pm \sqrt{17}}{2} \\\\x = \frac{-7 + \sqrt{17}}{2} , \ , \frac{-7 - \sqrt{17}}{2}[/tex]