7)
slope = (1+3)/(-1+10) = 4/9
y = mx + b
1 = 4/9(-1) + b
b = 1 + 4/9
b = 13/9
equation
y = 4/9x + 13/9
answer is D.y = 4/9x + 13/9
8)
y = 3x - 3
perpendicular so slope = -1/3
passing thru (-7, 9)
equation
y - 9 = -1/3(x +7)
answer is D. y - 9 = -1/3(x +7)
