Page:The Algebra of Mohammed Ben Musa (1831).djvu/200

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text of which, together with a Persian commentary by Roshan Ali, was printed at Calcutta^[1] (1812. 8vo.) the following explanation is given (pp. 334. 335.),

“The side (of the equation) on which something is to be subtracted, is made complete, and as much is added to the other side: this is jebr; again those cognate quantities which are equal on both sides are removed, and this is mokābalah”. The examples which soon follow, and the solution of which Baha-eddin shows at full length, afford ample illustration of these definitions. In page 338, $1500-{\tfrac {1}{4}}x=x$ is reduced to $1500=1{\tfrac {1}{4}}x$; this he says is affected by jebr. In page 341, $7x={\tfrac {1}{2}}x^{2}+{\tfrac {1}{2}}x$ is reduced to $13x=x^{2}$, and this he states to be the result of both jebr and mokābalah.

The Persians have borrowed the words jebr and mokābalah, together with the greater part of their mathematical terminology, from the Arabs. The following extract from a short treatise on Algebra in Persian verse, by Mohammed Nadjm-eddin Khan, appended to the Calcutta edition of the Kholāset al Hisāb, will serve as an illustration of this remark.

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1. A full account of this work by Mr. Strachey will be found in the twelfth volume of the Asiatic Researches, and in Hutton’s Tracts on mathematical and philosophical subjects, vol. II. pp. 179-193. See also Hutton’s Mathematical Dictionary, art. Algebra.