Respuesta :
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
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