<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>2218-3620</journal-id>
<journal-title><![CDATA[Revista Universidad y Sociedad]]></journal-title>
<abbrev-journal-title><![CDATA[Universidad y Sociedad]]></abbrev-journal-title>
<issn>2218-3620</issn>
<publisher>
<publisher-name><![CDATA[Editorial "Universo Sur"]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S2218-36202021000600265</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[On the solvability of some boundary value problems for operator-differential problems in a finite interval]]></article-title>
<article-title xml:lang="es"><![CDATA[Sobre la solubilidad de algunos problemas del valor límite para problemas diferenciales por el operador en un intervalo finito]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Huseyn Ahmadov]]></surname>
<given-names><![CDATA[Humeyir]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Zulfiqar Humbataliev]]></surname>
<given-names><![CDATA[Rovshan]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Institute of Education of the Republic of Azerbaijan  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Azerbaijan</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Azerbaijan State Pedagogical University  ]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Azerbaijan</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2021</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2021</year>
</pub-date>
<volume>13</volume>
<numero>6</numero>
<fpage>265</fpage>
<lpage>274</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_arttext&amp;pid=S2218-36202021000600265&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_abstract&amp;pid=S2218-36202021000600265&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_pdf&amp;pid=S2218-36202021000600265&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[ABSTRACT In this paper, conditions are obtained for the coefficients of one class of operator-differential equations of the fourth order, which ensure the solvability of some boundary value problems correctly posed for these equations. Moreover, a connection is indicated between the solvability of boundary value problems and the exact value of the norm of operators of intermediate derivatives in some subspaces.]]></p></abstract>
<abstract abstract-type="short" xml:lang="es"><p><![CDATA[RESUMEN En este trabajo, se obtienen condiciones para los coeficientes de una clase de ecuaciones operador-diferenciales del cuarto orden, que aseguran la solvencia de algunos problemas de valor límite correctamente planteados para estas ecuaciones. Además, se indica una conexión entre la solvabilidad de los problemas de valor límite y el valor exacto de la norma de operadores de derivados intermedios en algunos subespacios.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Equations]]></kwd>
<kwd lng="en"><![CDATA[solvability of boundary]]></kwd>
<kwd lng="en"><![CDATA[mechanics]]></kwd>
<kwd lng="en"><![CDATA[mathematical-physic]]></kwd>
<kwd lng="es"><![CDATA[Ecuaciones]]></kwd>
<kwd lng="es"><![CDATA[solvencia de límites]]></kwd>
<kwd lng="es"><![CDATA[mecánica]]></kwd>
<kwd lng="es"><![CDATA[física-matemática]]></kwd>
</kwd-group>
</article-meta>
</front><back>
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