Which of the following is not a linear equation in one variable?

A linear equation in one variable is an equation that can be written in the form "ax + b = 0," where "x" is the variable, and "a" and "b" are constants.

Let's examine each equation given:

33z + 5 = 0 :- This equation is linear in one variable (z).

33(x + y) = 0 :- This equation can be simplified to 33x + 33y = 0, which is not a linear in one variable and it has two variables, 'x' and 'y'.

2x = 3 :- This equation is linear in one variable (x).

3y = 99 :- This equation can be simplified to Y = 33, which is linear in one variable (y).