Question 722831
{{{3[(x+3)^(3/4)]=81}}}.... Those grouping symbols do not carry into rendering.  The given equation is the same as 3((x+3)^(3/4))=81, which is renderable as {{{3((x+3)^(3/4))=81}}}


The 3 is a factor.  The square brackets are grouping symbols.  Divide both sides of the equation by 3.


Continue with {{{(x+3)^(3/4)=27}}}