y = mx + b
slope(m) = -3/8
(5,-4)...x = 5 and y = -4
now we sub and find b, the y int
-4 = -3/8(5) + b
-4 = -15/8 + b
-4 + 15/8 = b
-32/8 + 15/8 = b
-17/8 = b
y = -3/8x - 17/8.....add 3/8x to both sides
3/8x + y = -17/8...multiply everything by 8
3x + 8y = - 17 <=== standard form