
Michael R. answered 06/03/20
Middle School Math Teacher- Algebra, Calculus, SAT prep, Stats
Solving polynomials greater than quadratics is actually quite difficult and not something one will likely have to do aside from special cases where the polynomial can be reduced to a quadratic.
A quadratic is an equation of the form ax2+bx+c=0, and as you may or may not know can be solved by the following formula: x=(-b±√(b2-4ac))/2a.
Adding and subtracting polynomials is quite simple, as it just involves combining like terms. For example, say I have two quadratic polynomial functions, p1(x)=2x2+3x+1 and p2(x)=x2+4x-2, then p1(x)+p2(x)=(2+1)x2+(3+4)x+(1-2)=3x2+7x-1, the same goes for subtracting polynomials.
Multiplying polynomials is a bit more difficult as it involves using FOIL (Front, Outside, Inside, Last) multiplication. For example lets take two simple polynomials, a(x)=x2+1 and b(x)=x3+2.
a(x)*b(x)=(x2+1)(x3+2)=(x2*x3)+(x2*2)+(1*x3)+(1*2)=x5+x3+2x2+2