x^2 -15x =0

Question

x^2 -15x =0

anonymous · Answer

$x^2-15x=0$
Looks like a factoring question to me.
What can you divide both terms by?

bbb911 · Answer

the 15 by 3 and 5 right?

anonymous · Answer

No, what is common to both terms?
One term is $x^2$ and the other is $-15x$. A term is the coefficient, variable and exponent.

bbb911 · Answer

they both have x's right

bbb911 · Answer

i wasn't so sure if this would  be it. (x    ) (x     ) to start with

anonymous · Answer

Right, so divide both terms by x and you get $\large{x(x-15)}$. If there was a constant term (other than 0), then you would have used the reverse FOIL form. (x    )(x   )

bbb911 · Answer

so the x would be on the outside right? then the answer would be x=15 right

anonymous · Answer

No. You would still set each = to 0 to solve.

anonymous · Answer

$x = 0$ and $ x-15 = 0$

bbb911 · Answer

so would it be15x=0 but because the the negative now turns into a postive

anonymous · Answer

I shouldn't have said no... $x=15$ is one answer.

anonymous · Answer

This is a second degree polynomial and therefore has two answers.

bbb911 · Answer

oh so there's more than one answer?

anonymous · Answer

Just the same as if it had factored to this format:
$(x-2)(x+5)$
$x-2=0$ and $x+5=0$

anonymous · Answer

Only in this case it factors to:
$x$ and $x-15$

bbb911 · Answer

oh ok thank ou so uch :)

anonymous · Answer

Your welcome.