In class, did you cover
b=y-intercept. This is the value of y when x=0. It is the position in which the line crosses the y-axis.
The question was...
Given the graph of an equations, where would you look on the graph to find the solutions to the equation that goes with the graph?
The answer I would suggest is...
I would look at the position on the y-axis when x=0. This is the y-intercept, also known as b in the equation known as y=mx+b. The m in such equation is the slope. This is the difference between any two coordinates. It is the value of each y-coordinate, subtracted from each other. Such subtracted result is divided by the corresponding two x-coordinates, also subtracted from each other.