Answer:
0
Step-by-step explanation:
42=42+9b
We move all terms to the left:
42-(42+9b)=0
We add all the numbers together, and all the variables
-(9b+42)+42=0
We get rid of parentheses
-9b-42+42=0
We add all the numbers together, and all the variables
-9b=0
b=0/-9
b=0