If the equation of a line is y=mx + b where m is the slope and b is the y intercept you can find the m value by finding the slope between these two points.
Slope = the rise over the run or the change in y over the change in x
take the y values first -6 to -4 is a rise of 2.
take the x values next - 2 to -5 is a run of -3
so your m value is -2/3x
The easiest way to find the y intercept is to plot points until this crosses the y-axis.
You will find the y intercept is -22/3 which is your b value.
The equation for the line is y=-2/3x -22/3