9) given slope is m= -1 and the point slope form of line is y-y1=mx-x1
so first find a option with the slope -1 and we see voila! there's only one option B with -1 slope
10) given (x1,y1)= (2,-4) and slope m= -5/2
y-y1=mx-x1
y-(-4)= (-5/2)x-2
y+4=(-5/2)x -2 <---Answer
