Respuesta :

Answer:

-27

Step-by-step explanation:

f(x) = 3(x-1)(x-7)

     = (3x-3)(x-7)

     = 3x^2 - 24x + 21

when f(x) = 0, x = 7 or 1

x-intercept of vertix of the graph = (7+1 )/ 2 = 4

f(x) attains it's minimum when x = 4

The minimum output value = 3(4-1)(4-7)  = -27