Final answer:
Without further information, it is not possible to determine the numerical value for the length of HJ based on the expressions given for HJ (5x+7) and HI (6x-9).
Step-by-step explanation:
The question is asking to find the length of HJ in terms of the given expressions for HJ and HI. However, the provided information is insufficient to determine the numerical length of HJ as we do not have enough information to form an equation. Additional information is required, such as the relationship between HJ and HI or other constraints within the context of the problem. If HJ and HI are sides of the same figure or there is some known proportion or equality, then we'd have a means to solve for 'x' and consequently find the length of HJ.
As is, we cannot answer the question definitively without additional detail on how HJ and HI relate to each other.