How is the resolution determined when bartering items of differing values during illness, such as trading grain worth thirty for grain worth ten or fifteen?

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When bartering items of unequal value, such as a measure of wheat worth thirty for a measure worth ten or fifteen, the calculation method chosen in the view of the Qadi and those who agree with him must be followed, as equality in exchange is a condition for the validity of a sale unless determined otherwise by this method. This is calculated by algebraic resolution where the exchange involves an item worth three times the other; the concession is two-thirds of the higher value item, leaving one-third of that item, which equals the concession amount. This calculation determines the equitable share.