“Transform the Multivariate to Unitevariate System and Using Elimination and Duplication Matrices With Some Applications”. 2021. Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ) 30 (2): 35-47. https://doi.org/10.55562/jrucs.v30i2.364.