Respuesta :

lasagna69420

Answer:

the value is -5 and the root is 4

Ver imagen lasagna69420
Ver imagen lasagna69420
MathPhys

Step-by-step explanation:

3x² + kx − 28 = 0

(a) One of the roots is -2⅓ = -7/3.  So the value of k is:

3(-7/3)² + k(-7/3) − 28 = 0

49/3 − 7/3 k − 28 = 0

49/3 − 28 = 7/3 k

49 − 84 = 7k

k = -5

(b) 3x² − 5x − 28 = 0

(3x + 7) (x − 4) = 0

x = -7/3 or 4

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