in order to find the slope of the line, we can pick two points on the line and plug them into the slope equation (y2-y1)/(x2-x1)
two points could be (-3,-3) and (0,-1)
slope = (-1 - -3)/(-3-0) = 2/3
an equation for the line can be written using the slope and the y intercept (y value when x=0)
y = (2/3)x - 1
to find the a and b values look at the graph along the x and y axis. you can also count 2 points up and 3 points left from (0,-1) until you reach that point since it has the same slope. a=3, b=1
the y coordinate when x=0 is -1 because that is the y intercept