Respuesta :

Step-by-step explanation:

A. 2(10)-(-10)

20 -(-10) -------> (-)×(-) =(+)

20 + 10

30

B.29 + 1

30

A.20-(-10).
20+20
30
30

B.29+1

C.-29-1
-30

The value in part a equals 30
Hope that helps:)