Given −7 is one of the roots of the quadratic equation
(x + k)2 = 16, where k is a constant, find the values of k.

Respuesta :

Answer:

  k = {3, 11}

Step-by-step explanation:

Taking the square root of the given equation, we find ...

  x +k = ±4

For x = -7, this is ...

  -7 +k = ±4

  k = 7 ±4 = {3, 11}

Possible values of k are 3 and 11.

[tex]\huge\bf\underline{\underline{\pink{A}\orange{N}\blue{S}\green{W}\red{E}\purple{R:-}}}[/tex]

Taking square root on the both sides of equation (x + k)² = 16 we get,

[tex]\implies\rm{( {x + k)}^{2} } = 16[/tex]

[tex]\implies\rm{x + k = ± 4}[/tex]

Making two conditions for ± 4 i.e

1) x + k = 4

[tex]\implies\rm{ - 7 + k = 4}[/tex]

[tex]\implies\rm{k = 4 + 7}[/tex]

[tex]\implies\rm{k = 11}[/tex]

2) x + k = -4

[tex]\implies\rm{ - 7 + k = - 4}[/tex]

[tex]\implies\rm{k = - 4 + 7}[/tex]

[tex]\implies\rm{k = 3}[/tex]

  • Thus the values of k can be either 11 or 3.