Question 359053
Use the FOIL Method,
{{{(x^3-x^4)(x^3+x^4)=x^3x^3+x^3x^4-x^4x^3-x^4x^4}}}
{{{(x^3-x^4)(x^3+x^4)=x^(3+3)+x^(3+4)-x^(4+3)-x^(4+4)}}}
{{{(x^3-x^4)(x^3+x^4)=x^(6)+x^(7)-x^(7)-x^(8)}}}
{{{highlight((x^3-x^4)(x^3+x^4)=x^(6)-x^(8))}}}