Question 1204219
 {{{h^3-25}}}...... rewrite {{{25}}} as {{{(root(3,25))^3}}}

 {{{h^3-(root(3,25))^3}}}.....now you have the difference of cubes and apply the rule {{{x^3-y^3=(x-y)(x^2+xy+y^2)}}}

in your case {{{x=h }}} and {{{y =root(3,25)}}}

{{{ h^3-(root(3,25))^3=(h-root(3,25))(h^2+h*root(3,25)+(root(3,25))^2)}}}