\ . 



— 423 — 



QiKilifcr vcnsu.s radices el draijme inter sc midfipliceutw. 



Ad inslar honmi mulliplicamus res quibus diminuilur vel superhabundal 

 numcrtts vel ipse numero. Verbi gratia^ ponanlitv 10 drayme minus duabits re- 

 bus mulliplicanda in 10 dragmas minus tribus rebus. Mulliplicamus duas res 

 dimimUas in 3 res diminulas; el erunt G census addendi. Item 1 dragmas in 

 10 fiunt 100, 2 res diminulas in 10 dragmas, fiunt 20 res minuende, 10 in 

 3 res diminulas., fiunt 30 res minuende. Summa igitur huius multiplicalionis 

 est 6 census el 100 dragme minus bO rebus (I). Item mulliplicenlur ^0 drngme 

 plus duabus I'ebus in 10 dragmas minus tribus rebus res addite in tres res 

 diminulas fiunt G census minuendi, 10 in 10 fiunt 100 dragme., 2 res addite 

 ()i 10 fiunt 20 res addite., 10 i;t 3 res diminulas fiunt 30 res diminulas. Re- 

 slauramus ergo per 20 priores res res 30 diminulas., el sic erunt tanlum 10 

 res diminute. E.x hac ergo mttlliplicatione insurgunt i 00 dragme minus 6 cen- 

 sibus cMO rebus (2). Similiter agendum est in mulliplicatione numerorum cumfra- 

 ctionibus propositorum. Proponantur enim 2 dragme et tereia multipUeande in 

 duas dragmas et unam quarlnm; tereia in quartam fit 12, 2 in 2 fiunt 4, 

 (ercm in 2 faint due tercie, 2 in quartam fit semis, totum ergo fit 5 dragme 

 et 3 12". Item 2 dragme minus tereia in duo minus quarta. Ducatur tereia 



la quantiU 



Sx — 2X2 

 da 



S 



«■ 



2 



la quanlita 



Sx — 4 



(la 



S 

 r 



(1) Cioi 



(2) Cioj: 



(10— 2j)(10 — 3j) = 100 — 20x — 30x -+- 6x= 

 = 6x' -+- 100 — 50x. 



(10 ■+- 2x)(10 — 3x) = 100 -+- 20x — 30x — 6x' 

 = 100 — ex" — lOx. 



