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HELP ASAP!!!
What are the exact solutions of x2 − 3x − 1 = 0 using x equals negative b plus or minus the square root of the quantity b squared minus 4 times a times c all over 2 times a?

x = the quantity of 3 plus or minus the square root of 5 all over 2
x = the quantity of negative 3 plus or minus the square root of 5 all over 2
x = the quantity of 3 plus or minus the square root of 13 all over 2
x = the quantity of negative 3 plus or minus the square root of 13 all over 2

Respuesta :

Answer:  Choice C

Explanation:

The given equation is in the form [tex]ax^2+bx+c=0[/tex], where,

  • a = 1
  • b = -3
  • c = -1

Use the quadratic formula to get the following

[tex]x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}\\\\x = \frac{-(-3)\pm\sqrt{(-3)^2-4(1)(-1)}}{2(1)}\\\\x = \frac{3\pm\sqrt{9+4}}{2}\\\\x = \frac{3\pm\sqrt{13}}{2}\\\\[/tex]

The last equation matches with choice C.

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