What is the value of y if x=30?

For which rational expression is -2 an excluded value of x?

Need ! give step by step solutions on how to solve number one \frac{9-2\sqrt{3} }{12+\sqrt{3} } number two x+4=\sqrt{13x-20} number three (domain and range) f(x)=2\sqrt[3]{x} +1

Consider the system: y = 3x + 5 y = ax + b what values for a and b make the system inconsistent? what values for a and b make the system consistent and dependent? explain