Hi, what would not be a linear equation? I know a linear equation is y=mx + b, which m represents slop and b is the y-intercept. For example, it be it costs five dollars per hour to rent a movie and a two-dollar fee when purchasing the movie, This as a linear equation would be y= 5x + 2. But can a linear equation be y= 3/x + b or y= x (square root sign on it) + b?