Only 25 and 28 are functions.
A function must have only one y value per x value. For 26, the y value of 0 and multiple others have two different y values. For 27, all x values less than 0 have multiple y values.
First of all: subtract 3 from 3x then from 2y then divide
Answer:
-2; -7
Step-by-step explanation:
Hello, the graph is split in two lines, right?
Go to the first line at the left and move to the right until you reach the end of the line, which is for x = -1,
*** This is the meaning of x tending to
***
which value can you see for the y-axis? 
Now, go to the second line at the right and move to the left until you reach the end of the line, which is for x = -1,
*** This is the meaning of x tending to
***
which value can you see for the y-axis?

Thanks
One field is 25 + 45 + 25 + 45 = 140 feet
Second field is 40 + 60 + 40 + 60 = 200 feet.
Therefore, all together, the two fields are 340 feet in perimeter together