Answer:
The value of x is -9, 3/4 and 3.
Step-by-step explanation:
In order to find the value of x, tou have to let f(x) equals to 0 :
Let f(x) = 0,
(x-3)(x+9)(4x-3) = 0
x - 3 = 0
x = 3
x + 9 = 0
x = -9
4x - 3 = 0
4x = 3
x = 3/4
x-10=3
x+10-10=3+10
x=13