Respuesta :

Answer:

The answer is A

[tex]x=\frac{1+i\sqrt{143} }{8}[/tex] and [tex]x=\frac{1-i\sqrt{143} }{8}[/tex]

Step-by-step explanation:

∵ 4x² - x + 9 = 0 ⇒ is quadratic equation

∴ [tex]x=\frac{-b+\sqrt{b^{2}-4ac } }{2a}[/tex]

∴ [tex]x=\frac{-b-\sqrt{b^{2}-4ac } }{2a}[/tex]

Where a is the cooficient of x² , b is the cooficient of x and c is the numerical term

a = 4 , b = -1 and c = 9

∴ [tex]x=\frac{-(-1)+\sqrt{(-1)^{2}-4(4)(9) } }{2(4)} =\frac{1+\sqrt{1-144} }{8}[/tex]

  [tex]=\frac{1+\sqrt{-143} }{8}=\frac{1+i\sqrt{143} }{8}[/tex]⇒ i = √(-1)

∴ [tex]x=\frac{1-i\sqrt{143} }{8}[/tex]

∴The solutions are:

  x=[tex]\frac{1+i\sqrt{143} }{8}[/tex] and x=[tex]\frac{1-i\sqrt{143} }{8}[/tex]

Answer:

Choice A is correct answer.

Step-by-step explanation:

We have given a quadratic equation.

4x²-x+9  = 0

We have to find the solution of given equation.

We use following quadratic formula to find the solution.

x  = (-b±√b²-4ac) / 2a

In given equation, a  = 4 , b  = -1 and c  = 9

Putting given values in quadratic formula, we have

x  = (-(-1)±√(-1)²-4(4)(9) ) / 2(4)

x  = (1±√1-144) / 8

x  =  (1±√-143 ) / 8

x  = (1±√-1√143) / 8                             ∵ i  = √-1

x  = (1±√143i) / 8

hence,The solutions are (1+√143)/8 and (1-√143)/8.