Respuesta :

Answer:

10b^2

Step-by-step explanation:

30b^2: 5 * 2 * 3 * b^2  

80b^2: 5 * 2 * 2 * 2 *2 * b^2

20b^3: 5 * 2 * 2 * b^2 * b

The highest common factor is in bold script. It is 10b^2