Question

answers can be expressed in exact form, even one in decimal form, whereas with the graph, you can only tell the position when it is an exact integer value : accurate decimal answer
-on the other hand , graphs are fairly easy to plot, little algebra.
-however, it is difficult to draw a graph with more than two unknowns by hand.
-graphs are a disadvantage also in that the required solution might be way out of range of the graph, where scaling may result in an approximate answer, which may not be desirable