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An equation in the form ax2+bx+c=0 is solved by the quadratic formula. The solution to the equation is shown below.x=−7±√ "572" What are the values of a, b, and c in the quadratic equation?
A: a= 1, b= -7, c = -2
B: a = 1, b= 7, c = -2
C: a = 2, b = -7, c = -1
D: a = 2, b = 7, c = -1

Respuesta :

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Answer:

B: a = 1, b= 7, c = -2

Explanation:

[tex]\sf Quadratic \ Equation : \dfrac{-b\pm \sqrt{b^2 - 4ac} }{2a}[/tex]

Knowing This:

solve for b

  • -b = -7
  • b = 7

solve for a:

  • 2a = 2
  • a = 1

solve c:

  • b² - 4ac = 57
  • 7² - 4(1)(c) = 57
  • -4c = 57 - 49
  • -4c = 8
  • c = 8/-4 = -2

Let's see

  • x=-b±√b²-4ac/2a

On comparing

  • -b=-7
  • b=7

And

  • 2a=2
  • a=2/2
  • a=1

So

  • b²-4ac=57
  • 7²-4c=57
  • 4c=49-57
  • 4c=-8
  • c=-2

Option B

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