Question

So I was doing pretty good with these until I came to this one I tried all of my answers but none of them worked so I must have done something wrong
Here are the choices

A) f(x)=x(x+3)(x+4)
B) f(x)=3x(x+3)(x+4)
C) f(x)=x(x+5)(x+4)
D) f(x)=x(3x+1)(x+4)

Answer 1

f(x)=x^3 +7x^2 +12x this is the equation I'm having trouble with

Answer 2

first factor out an x
what is the quadratic?

Answer 3

x^2 + 7x + 12
what are the factors of +12 that add up to +7
we will use +3 and +4
so we get (x +3)(x+4) when we factor the quadratic

back to the original
x^3 +7x^2 +12x = x(x+3)(x+4)

Answer 4

Thank you so much @triciaal

Answer 5

oh you are welcome