In the diagram below of parallelogram STUV, SV = x + 3,VU = 2x - 1, and TU = 4x - 3.What is the length of SV?

in this parallelogram side TU and side SV will be equal
so, TU = SV
4x - 3 = x +3
4x - x = 3 + 3
3x = 6
x = 6/3
x = 2
so the length of SV is,
SV = x + 3, put x = 2
SV = 2 + 3
SV = 5
so the length of SV is 5