Complex sentence: In 1683, Seki pushed ahead with elimination theory, based on resultants, in the "Kai-fukudai-no-hō" (解伏題之法,); and to express the resultant, he developed the notion of determinant.
Split into simpler sentences: In 1683, Seki pushed ahead with elimination theory, based on resultants, in the "Kai-fukudai-no-hō" (解伏題之法). To express the resultant, he developed the notion of determinant.