Advances in polynomial algebra were made by mathematicians during the Yuan era. The mathematician Zhu Shijie (1249–1314) solved simultaneous equations with up to four unknowns using a rectangular array of coefficients, equivalent to modern matrices. Zhu used a method of elimination to reduce the simultaneous equations to a single equation with only one unknown. His method is described in the Jade Mirror of the Four Unknowns, written in 1303. The opening pages contain a diagram of Pascal's triangle. The summation of a finite arithmetic series is also covered in the book.
When was Zhu Shijie born? When did Zhu Shijie die? What modern math concept did Zhu Shijie do work similar to? What type of math was advanced during the Yuan? When did Zhu publish 'Jade Mirror of the Four Unknowns'?