Multiplying polynomials can be done using three methods:
1. The distributive property, which involves multiplying each term of one polynomial with each term of the other.
2. FOIL (First, Outer, Inner, Last), which is a shortcut used for multiplying two binomials by multiplying the first, outer, inner, and last terms.
3. The box method, which involves drawing a box and writing one polynomial above and beside the box before distributing the multiplication similar to the distributive property.