Simply combine the exponents of the variables (if needed). About the integers, just multiply as usual. We can use the Latice Method in multiplying polynomials.
For example, (2x + 3)(3x + 5)
2x +3
3x 6x² 6x
+5 10x 15
Add them.
6x² + 6x + 10x + 15
6x² + 16x + 15
In multiplying binomial, we can use the FOIL method but using Latice is better that you can use it always. Hope you understand my explanation ☺ even tho it's not that clear. But still, I hope it helped.