For a linear graph (i.e. the curve is a straight line)
y=mx+B
m = -2 is the slope
B = 3 is the y intercept.
Put y=0 and solve for x, gives the x-intercept as 1.5
So the given graph is a straight line decreasing (as x increases) with a slope of -2, x-intercept (1.5,0) and y-intercept (0,3).