Jade Mirror of the Four Unknowns
He then solved the high-order equation by Southern Song dynasty mathematician Qin Jiushao's "Ling long kai fang" method published in Shùshū Jiǔzhāng ( “Mathematical Treatise in Nine Sections” ) in 1247 ( more than 570 years before English mathematician William Horner's method using synthetic division ) . 
<triplet> Qin Jiushao <subj> Southern Song <obj> country of citizenship <triplet> Mathematical Treatise in Nine Sections <subj> Qin Jiushao <obj> author