1
\(f\left(x\right)=\left(3x^3-x^3\right)+2x^2+5x-\left(4-11\right)\)
\(f\left(x\right)=2x^3+2x^2+5x-7\)
\(g\left(x\right)=x^2+4-3x^2-3x^2+7x^3-1\\ g\left(x\right)=7x^3+\left(x^2-3x^2-3x^2\right)+\left(4+1\right)\\ g\left(x\right)=7x^3-5x^2+5\)
2
f(x)=2x3 + 2x2 + 5x -7
+ g(x)=7x3 - 5x2 +5
----------------------------------------------------
f(x)+g(x)=9x3 - 3x2 + 5x -2
3
f(x)=2x3 + 2x2 + 5x -7
- g(x)=7x3 - 5x2 +5
----------------------------------------------------
f(x)-g(x)=-5x3 + 7x2 + 5x -12