20210207004100.0 Jurnal Math-UMB.EDU. 2715-4912 2339-2754 2715-4912 2715-4912 Jurnal Math-UMB.EDU (Online) http://jurnal.umb.ac.id/index.php/math Jurnal Math-UMB.EDU (Online) Indonesia Jurnal Math-UMB.EDU. 2715-4912