The answer is a. to be a function there can’t be an x value that is the same to a different y value. so as an example (6,7) (3,2) (5,6) (6,3) is not a function because 6 appears 2 times as an x value but with different y values. but you can have the same y value.
They are different symbols
Y+2(y+16)=5
y+2y+32=5
3y=-27
y=-9
x=-9+16
x=7
Here's link to the answer:
tinyurl.com/wpazsebu
X=1.2
y=-10.7
-x+(-y)=-(1.2)+(-(-10.7)=-1.2+10.7=9.5
Answer: -x+(-y)=9.5
