remember
[tex]\sqrt{x^2}=x[/tex]
and
[tex]\sqrt[3]{x^3}=x[/tex]
so
[tex]\sqrt{x^2}+\sqrt[3]{y^3}=[/tex]
[tex]x+y[/tex]
another way is this:
remember that
[tex]\sqrt[n]{x^m}=x^\frac{m}{n}[/tex]
and remember that [tex]\sqrt{x}=\sqrt[2]{x}[/tex]
so
[tex]\sqrt{x^2}+\sqrt[3]{y^3}=[/tex]
[tex]x^\frac{2}{2}+y^\frac{3}{3}=[/tex]
[tex]x^1+y^1=[/tex]
[tex]x+y[/tex]
