Question

How to solve polynomial by factoring and using the zero product principle for x^3+3x^2=4x+12

Answer 1

Answer:

The solutions to the equation are -3,-2,2

Step-by-step explanation:

x^3+3x^2=4x+12

Subtract 4x +12 from each side

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

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

I will use factoring by grouping

x^3+3x^2     -4x-12=0

I will factor out x^2 from the first group and -4 from the second group

x^2 (x+3) -4(x+3) =0

Now we can factor out (x+3)

(x+3) (x^2-4) =0

We can use the zero product principle since the right hand side is equal to 0

x+3 =0            x^2-4 =0

x+3-3=0-3        x^2 -4+4=0+4

x=-3                    x^2=4

                           Take the square root of each side

                            sqrt(x^2) = sqrt(4)

                                      x=±2

The solutions to the equation are -3,-2,2