Respuesta :

Answer:

The answer is 30  

Step-by-step explanation:

To get a.b  

For a = <wa, za> and b = <wb, zb>, the dot product represents multiplication sign.

We say,  

 a•b = (wa)(wb) + (za)(zb)

The next step is to substitute the given information into the above equation we generated.

Then we say,  

 a•b = 5•4 + 2•5

 a.b = 20 + 10

 a•b = 30

The answer is 30