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First find out the underlying cause for it.
If the leaves are yellow and it withers, it may be due to lack of sunlight or lack of space for the root in the pot. Some times overwatering may lead to yellowing of the plants.
If first one is the cause, then place the plant in the sunlight.
If second one is the cause, then you need to do re-potting. Remove the plant and trim the excess fibrous root (not the tap root). Then re-plant it.
Any more clarifications.....