Notice that the left sides of these equation are identical. So, their right sides are equal: -8/3x + 4 = -8/3x - 1. Cancel the common term -8/3x in both sides. You will get 4 = -1. It NEVER can be true. Hence, the original system HAS NO SOLUTIONS.
Slopes are identical, but b, or y-intercepts are DIFFERENT, so the lines are parallel, so: