8 because 12-4=8. Im writing this part for the 20 characters
We are given

We can write it as

we can see that 2y is in first two terms
and -8 is in last two terms
so, we can factor it out

now, we can see that x+4 is common in both terms
so, we can factor it out

we can see that
x+4 is one of factor of terms
so, option-B..........Answer
The perimeter is composed of two straight parts and two semicircles. We can use this to break down the problem.
We can find the straight parts easily. They are given in the problem.
straight parts: 82 x 2 = 164 m
The two semicircles make a circle. We just have to find the circumference of a circle with a diameter of 66 cm to get the length of the semicircles.
semicircles: 2(π)(66/2) = 66(3.14) = 207.24 m
answer: 164+207.24 = 371.24 m
In this question the answer is x is equal to exactly 1.749... Or 1.75