Question

decide whether y is a function of x.
y=-3x-4

Answer 1

Solve for x.
y+4=-3x
y+4/-3=x
So, x=(y+4)/-3
Is that a function?

Answer 2

It may be a little out of context, but If im interpreting this right, then by the definition of a function, if there is no more than 1value of y that can equal 1 or more x value, then y is a function of x.
for example. y^2 = x is not a function of x because:
y^2 = x --> y =( + or -)sqrt(x). that means there is more than 1 possible value of y for a single value of x.
the same idea applies to finding if x is a function of y. if there can be only one x value or 1 or more values of y, then x can also be a function of x.

Answer 3

yes

Answer 4

2nd and 4th quadrant of x and y has a function