If x + yz = 2, then what is the value of [ yy - z ] + [ xx - z ]?

Answer: Option C

Take x = 3, y = 1, z = 2, satisfy the equation
$$\therefore \frac{y}{y-z}+\frac{x}{x-z}\Rightarrow \frac{1}{-1}+\frac{3}{1}=2$$