Question 1097259
{{{(7x^4-7x^3-5) -(2x^4+5x^3-4)=(7x^4-2x^4)+(-7x^3-5x^3)+(-5-(-4))}}}
{{{(7x^4-7x^3-5) -(2x^4+5x^3-4)=(5x^4)+(-12x^3)+(-5+4)}}}
{{{(7x^4-7x^3-5) -(2x^4+5x^3-4)=5x^4-12x^3-1}}}