The answer I got was a=5. Hope this is correct and hope it helped
Answer:x^3+y^3+x^2 y+y^2 x-xy
Step-by-step explanation:
X+y(x^2 +y^2)- X y
Expand the bracket
X^3 +xy^2 +yx^2 -xy
Not addition, since

and 0 doesn't belong to the set.
Not subtraction, since

.
It is closed under multiplication. The set appears to contain all non-zero multiples of 3.
Not division, since dividing some of the numbers results in rationals which do not belong to the set.
What other operations are you supposed to consider?
Answer:
The answer is the 3rd one, x is shifted left 6 units and up 2 units.
Step-by-step explanation:
-6 in graphs or coordinate planes, is moving to the left, or moving down. +2 in graphs or coordinate planes can mean moving up, or moving to the right. So the 3rd one is your answer.
12.5 meters is the width i think