Question

Factor f(x)= 3x³+5x²-47x+15 into linear factors given that -5 is a zero of f(x)

Answer 1

if  -5 is a zero then f(x) is divisible by (x + 5)

the quotient when F*x) is divided by x + 5  is  :-
3x^2 - 10x + 3
this factors to 
(3x  - 1)(x  -  3)

so the answer is (x + 5)(3x - 1)(x -  3)