First we'll substitute
with 

Then we can separate this.

Then we'll solve this.



Then we'll plug in to find the extraneous solutions (if any)

Answer:
the answer should be c.
Step-by-step explanation:
here's why....A uses 4 more which is adding. B uses 4 fewer which is subtracting and D does not complete so it should be C.
Answer:8 12 and 20
Step-by-step explanation:I googled it
Answer:
assuming the squares are 1cm by 1cm
area 7
perimeter 16
Step-by-step explanation:
it just works