Answer:
To find the value of x such that the quadrilateral is a parallelogram, you need to solve for x in the equation 2x+1 = 3x - 1. This gives x = 1. The perimeter of the parallelogram is then 2x + x² - 5 + x² - 7 + 3x - 1 = 4x² - 13. Substituting x = 1 gives the perimeter as 4 - 13 = -9.