Answer:

Step-by-step explanation:
add 4 on both sides
leaves you with 15 on the right side
you then divide by negative 2
since you divide by a negative you have to switch the sign
Answer:
the mean of it all will increase
Step-by-step explanation:
The radius would be 40.82 divided 2 and that is 20.41 and the diameter would be 40.82 times 2 and that is 81.54