Author/Authors :
كنيياهينا، ويكتوريا نويسنده Department of Mathematics, Gomel Engineering Institute of MES of the Republic of Belarus, Gomel, Belarus Kniahina, Viktoryia Kniahina , موناخو، ويكتور نويسنده Department of Mathematics, Gomel F. Scorina State University, Gomel, Belarus Monakhov, Viktor