Question

solve
x^3-12x-65=0

Answer 1

I can solve it by cardon's method , ok ?

Answer 2

@msingh ?

Answer 3

this can be factored

Answer 4

the factors of 65 = {+-1, +-5, +-13, +-65}
for x=5 will satisfies as an solution of equation above, it means one of the factor is (x-5)

Answer 5

(x-5) (x^2+5x+13)=0

Answer 6

yep, then use the quadratic formula to get other solutions

Answer 7

looks they are be complex root, because x^2+5x+13 = 0 has the discriminant value
(D) < 0

Answer 8

@Eyad
ur answer is correct but how we get it

Answer 9

i am confused myself, how come the 12 turned into a 5?

Answer 10

As @RadEn Said , " the factors of 65 = {+-1, +-5, +-13, +-65}
for x=5 will satisfies as an solution of equation above, it means one of the factor is (x-5)"
Therefore Long divide to find the quadratic factor and factorise the quadratic if possible.
OR
You can use another way which is Archie Meade's

Answer 11

And another thing ,
x^3-12x=16
x(x^2-12)=16
and then ,
we can factorise 16 by many ways ,like 16(1)=8(2)=4(4) ..
so we can quickly discover
whether or not the function has an integer root.
If it does, the factoring is made simple.

Answer 12

that does clear it up, thanks. and its not even my question! haha

Answer 13

Yw :)

Answer 14

@Eyad
how this comes
x^3-12x=16

Answer 15

it was an example ,
In your question it will be
x^3-12=65 .

Answer 16

okay

Answer 17

@eyad
x(x^2-12)=13*5

Answer 18

Good job

Answer 19

that;s it
or is any next step