Graph the points and draw an aproximate line of fit that includes two of the points. Then using point-slope form find the linear equation of that line.
10-(-4)=m(-5-4) is 14=m(-9) solve for m and find the slope is aproxx -14/9 or -1.555. Then do some fancy math to find your y intercept and you come out with an aproxx line of fit of y=(-14/9)x+(20/9). Or you could plug these points into excel and have it spit out a trendline of y=(-1.26)x+(0.467)
