Through (5, -4), parallel to 8x + 3y =31

3y = -8x + 31

y = (-8/3) x + 31/3
slope = -8/3 of that line and of any line parallel to it
so:
y = (-8/3)x + b
we need b
-4 = (-8/3)5 + b
-4 = -40/3 + b
b = -12/3 +40/3 = 28/3
so
y = (-8/3) x + 28/3
3 y = -8 x + 28
8 x + 3 y = 28
or just
we know 8x + 3 y = something
8(5) + 3(-4) = 40-12 = 28
8 x + 3 y = 28