Question

4x^3-16x^2+12=0

I'm very confused, can someone help me solve the equation? :(

Answer 1

Your first step is to divide everything by 4.

Answer 2

Your next step would be to notice x = 1 solves the equation.

Answer 3

So is it -4x+3x?

Answer 4

No, you divide by 4:
x^3 - 4x^2 + 3 = 0
x = 1 solves this equation so factor out this solution:
(x - 1)(x^2 - 3x - 3)
Can you do the next step?

Answer 5

Is it supposely put equal to zero?

Answer 6

yes (x - 1)(x^2 - 3x - 3) = 0, i thought that much was clear.

Answer 7

Well it would be (x-1)=0
+1 +1 so x=1 , right?

Answer 8

Yes, I already told you that you must notice x = 1 is a solution. However, it is a cubic, so there are 3 solutions to x, so you have to find the remaining 2.

Answer 9

Is it 3 ?

Answer 10

Use the quadratic formula to find the two remaining roots.
In case you do not remember, for y=ax^2+by+c,
x=(-b +/- sqrt(b^2-4ac) )/(2a)
Use it on the remainder of the expression, namely (x^2 - 3x - 3).
It will not be a rational root (i.e. involves square-roots).