If 3x is one factor of 3x2 - 9x, what is the other factor?

Question

My parents make me do math problems over the summer because I'm kind of bad at it

And I keep doing this one over and over again but I keep getting it wrong

Help me please

Answer 1

3x^2-9x--->factor out 3

3(x^2-3x)--->factor out x

3x(x-3)--->factored

So, 3x is one factor, and the other factor is (x-3).

To check, set the expression equal to 0.

3x^2-9x=0

Now, set the factors equal to 0:

3x=0, x=0

and

x-3=0, x=3

So, if x=0 and x=3 are valid in the equation, the factors are correct.

3(0)^2-9(0)=3(0)-9(0)=0-0=0

And,

3(3)^2-9(3)=3(9)-9(3)=27-27=0

Since both are true, the factors are correct.

Peace

Answer 2

3x2 / 3x leaves x

so x - (9x / 3x)

or.. x-3

Answer 3

(x-3) the quotient you get by dividing the first binomial by your previously found factor ;)

Answer 4

You can factor out a 3 from both terms of 3x^2 - 9x to get

3(x^2 - 3x)

There's at least one x in both of the inside terms, so you can factor that out too

3x (x - 3)

So since 3x is one factor, the other factor is (x-3)