Whats the answer and steps to 5g+4(-5+3g)=1-g

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

If square root x = -7, then x= -49 true or false