Question

2n^3-30n^2+100n=0

Answer 1

factor out an \(2n\) first

Answer 2

So is it (2n ) ( n )
or is it (n ) (n ) ?

Answer 3

\[2n^3-30n^2+100n=0\]
\[2n\left(\frac{2n^3}{2n}-\frac{30n^2}{2n}+\frac{100n}{2n}\right)=0\]
\[2n\left((n ~~~~~~~~ )(n ~~~~~~ )\right)=0\]

Answer 4

Ok
whats next ?

Answer 5

simply the fractions if you haven't already
you should have something like this

\[2n(an^2+bn+c)=0\], , what is a,b,c?

Answer 6

wait ... isnt it like this

2n ( n^2 - 15n +50) =0

Answer 7

thats right

Answer 8

then square root it ?

Answer 9

to factorise the quadratic term in the brackets ,..

Answer 10

Sorry, i didnt understand that

Answer 11

your almost done
you just need to get
2n ( n^2 - 15n +50) =0
into this form

2n(( n ) (n ))=0

Answer 12

Oh .. i get it now

Answer 13

\[n^2 - 15n +50=(n~~~~~)(n~~~~~~~~)\]
can you do this in your head or should we use the quadratic formula?

Answer 14

Yeah, i can do it

Answer 15

so this is what i got , 2n (( n-5)(n-10))=0

Answer 16

so final answer i got is .. " n " can equal to 0 , 5 , or 10

Answer 17

great work,

now you have specified a question,

were we ment just to factorize the original expression , or find solutions for n?

Answer 18

ah, top stuff

Answer 19

Just find solutions for n

Answer 20

Thanks so much for the help

Answer 21

Now only a lot more to go :) , anyways thanks.

Answer 22

if you wanted to check you could do it this way

\[2(0)^3-30(0)^2+100(0)=?\]
\[2(5)^3-30(5)^2+100(5)=??\]
\[2(10)^3-30(10)^2+100(10)=???\]

if n is a solution then these should all equal zero

Answer 23

.. thanks !