Respuesta :

3x^2-27=0
3x^2 = 27
x^2 = 9
x^2 = +- 3
irspow
3x^2-27=0

3(x^2-9)=0  notice the difference of squares in the parentheses...

3(x+3)(x-3)=0

so x=±3  which means x=-3 or 3