If he leaves two sons, and ten dirhams of property and ten dirhams of debt by one of his sons, and bequeaths one-fifth of his property and one dirham to another man, then the calculation is:
Name the amount removed from the debt as x.
Add this amount to the property; then the amount is 10 + x dirhams.
Subtract one-fifth from this amount, because he has bequeathed one-fifth of his property, which is equivalent to 2 dirhams and one-fifth of x; the remainder is 8 dirhams and four-fifths of x.
Subtract also one dirham that he bequeathed, then the balance is 7 dirhams and four-fifths of x.
Divide this balance between his two children; each person will get 3 and a half dirhams and two-fifths of x; and this equates to one thing.
Subtract it by subtracting two-fifths of x from x. Then you will get three-fifths of x, equivalent to 3 and a half dirhams.
Complete that thing by adding to it two-thirds of the wealth; add the same amount to 3 and a half dirhams, which is 2 and a third dirhams; the sum is 5 and five-sixths.
This amount is x, which is the amount released from the debt earlier.
Express the calculation in the algebra method.