It is known that y + A is positively proportional to Z + a (a is a constant) and Z is positively proportional to X. is the relationship between Y and x a positive proportional function?

It is known that y + A is positively proportional to Z + a (a is a constant) and Z is positively proportional to X. is the relationship between Y and x a positive proportional function?

No, let y + a = K1 (Z + a), z = k2x, then y + a = K1 (k2x + a), so y = k1k2x + (K1-1) a is a linear function