Assuming initially that these are lengths of adjacent sides or measures of adjacent angles such that the side with length 2x+1 is parallel to the side with length y+3 and similarly for the other two sides, then:
2x+1=y+3 and 4y=4x-5. This applies to angles or sides.
So we have two equations: 2x-y=2 and 4x-4y=5.
We can solve using the simultaneous equations method or the substitution method.
Substitution method: y=2x-2, so 4x-4(2x-2)=5, 4x-8x+8=5, 3=4x, x=¾ and y=2×¾-2=-½.
This gives the side lengths of the parallelogram: 2½, -2, 2½, -2 which is clearly not possible, since negative lengths have no meaning. And it cannot apply to angles, because adjacent angles are supplementary (sum to 180 degrees or π radians (π=3.14 approx)).
So the initial assumption is incorrect.
That leaves us with the parallel sides, and opposite angles have equal measure:
2x+1=4y, so 2x-4y=-1 and y+3=4x-5, so 4x-y=8, y=4x-8.
2x-4(4x-8)=-1, 2x-16x+32=-1, 33=14x, x=33/14 and y=4(33/14)-8=66/7-8=10/7.
This time x and y are positive so this solution is feasible. The side lengths would be 40/7 and 31/7.
If x and y are angles then adjacent angles would be supplementary, but 40/7+31/7=71/7. This is neither 180 degrees or 3.14 radians. Therefore if the question has been correctly stated x=33/14 and y=10/7, giving side lengths 40/7 and 31/7. So (2x+1) (4y) (y+3) (4x-5) = (40/7) (40/7) (31/7) (31/7) are the sides given as two pairs of parallel sides.