X+y=57
y=x+15
x+x+15=57
2x=42
x=21
y=21+15
y=36
Multiply by -1 each time to get the answer in the output
F(x) = x4(x2 - 1)
f(-x) = (-x)4((-x)2 - 1)
f(-x) = x4(x2 - 1)
from above explanation it is clear that the function is even.
Question is confusing but 12/15 divides to 4/5 or rounds to 1
