Answer:
Slope intercept form does not dictate whether or not a function is linear. What determines if a function is linear is if there is one independent variable, one dependent variable, and it makes a STRAIGHT line. This function is linear because there are only 2 variables and a horizontal line.
Levi could have determined that the graph was linear by checking the conditions stated above or graphing it out. Then, he would see that y = 2 is a straight horizontal line with an independent and dependent variable.
Hope this helps!