factor this equation and solve

[cattyroughie]

x^3+64=0

 

[Deleted member 4993]

x^3+64=0

use

(a[sup:2db5xr5y]3[/sup:2db5xr5y] + b[sup:2db5xr5y]3[/sup:2db5xr5y]) = (a + b)(a[sup:2db5xr5y]2[/sup:2db5xr5y] - ab + b[sup:2db5xr5y]2[/sup:2db5xr5y])

Please show your work, indicating exactly where you are stuck - so that we know where to begin to help you.

 

[cattyroughie]

I got (x+4)(x^2-4x+16)

 

[DrMike]

I got (x+4)(x^2-4x+16)

Spot on.

So if (x+4)(x^2-4x+16)=0, then x+4=0 OR x^2-4x+16=0.

The first gives you one solution. The quadratic equation has no real solutions, but the quadratic formula would give you two complex solutions. Have you learned about complex numbers?

 

[cattyroughie]

yes