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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 :

Question has errors in typing that 572 should be √57/2

Because if it's 572 then 2a=1 so

  • a=1/2

Also

  • -7=1/2b
  • b=-7(2)
  • b=-14

c also comes different

If it's like what I said

then

  • 2a=2
  • a=1

and

  • -b=-7
  • b=7

By putting values

  • c=-2

Option B can be correct

semsee45

Answer:

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

Step-by-step explanation:

Quadratic Formula

[tex]x=\dfrac{-b \pm \sqrt{b^2-4ac} }{2a}\quad\textsf{when}\:ax^2+bx+c=0[/tex]

Given:

[tex]x=\dfrac{-7\pm\sqrt{57}}{2}[/tex]

Comparing the terms of the given x-value with those of the quadratic formula:

[tex]\dfrac{-b \pm \sqrt{b^2-4ac} }{2a}=\dfrac{-7\pm\sqrt{57}}{2}[/tex]

Therefore:

  • [tex]2a=2 \implies a=1[/tex]
  • [tex]b = 7[/tex]
  • [tex]b^2-4ac=57[/tex]

Using the found values of a and b to solve for c:

[tex]\implies b^2-4ac=57[/tex]

[tex]\implies (7)^2-4(1)c=57[/tex]

[tex]\implies 49-4c=57[/tex]

[tex]\implies -4c=57-49[/tex]

[tex]\implies -4c=8[/tex]

[tex]\implies c=-2[/tex]

In summary:   a = 1,  b = 7,  c = -2

[tex]\implies x^2+7x-2=0[/tex]

Therefore, option B is the correct solution.

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