a) $$2x^2-5x-3-4x^2+2x-7$$ b) $$1-2x-3x^2+x^3-3-3x+x^2-x^3$$ c) $$x^3-5x-2+x^3-4x^2+3$$ d) $$2x^4-4x^3-4x+2-3-5x^2-4x^3-2x^2$$
• a) $$2x^2-5x-3-4x^2+2x-7$$ $\class{color1}{2x^2}\class{color2}{-5x}-3\class{color1}{-4x^2}\class{color2}{+2x}-7= \class{color1}{-2x^2}\class{color2}{-3x}-10$
• b) $$1-2x-3x^2+x^3-3-3x+x^2-x^3$$ $1\class{color1}{-2x}\class{color2}{-3x^2}\class{color3}{+x^3}-3\class{color1}{-3x}\class{color2}{+x^2}\class{color3}{-x^3}=\class{color2}{-2x^2}\class{color1}{-5x}-2$
• c) $$x^3-5x-2+x^3-4x^2+3$$ $\class{color3}{x^3}\class{color1}{-5x}-2\class{color3}{+x^3}\class{color2}{-4x^2}+3 =\class{color3}{2x^3}\class{color2}{-4x^2}\class{color1}{-5x}+1$
• d) $$2x^4-4x^3-4x+2-3-5x^2-4x^3-2x^2$$ $\class{color4}{2x^4}\class{color3}{-4x^3}\class{color1}{-4x}+2-3\class{color3}{-4x^3}\class{color2}{-2x^2}=\class{color3}{-8x^3}\class{color2}{-5x^2}\class{color1}{-4x}-1$