Answer:

Step-by-step explanation:
The difference between two consecutive elements is 11.

Hence 
Whats the problem for this?
Formula for perimeter a+b+a+b
12+5+12+5= 17+17= 34 .34=P
Answer:
3)
Step-by-step explanation:
Draw the graph and youll see
Subtract 60 on both sides to get -40.
You are left with 40x=-40
Divide both sides by 40 to leave x by itself.
You get x=-1.