Выберите дробь, чтобы равенство стало верным.
<span class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: 400;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px;color: #1d1d1b;font-family: robotoregular, sans-serif;background-color: #ffffff" role="presentation" data-mathml="2b+4ab1+2a="><span class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: 400;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px;color: #1d1d1b;font-family: robotoregular, sans-serif;background-color: #ffffff" role="presentation" data-mathml="2b+4ab1+2a=">2b+4ab/1+2a=
<span id="MathJax-Element-6-Frame" class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: normal;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px" role="presentation" data-mathml="2b1+2a">1) 2b/1+2a
<span class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: 400;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px;color: #1d1d1b;font-family: robotoregular, sans-serif;background-color: #ffffff" role="presentation" data-mathml="2b+4ab1+2a="><span class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: 400;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px;color: #1d1d1b;font-family: robotoregular, sans-serif;background-color: #ffffff" role="presentation" data-mathml="2b+4ab1+2a=">
<span id="MathJax-Element-7-Frame" class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: normal;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px" role="presentation" data-mathml="2b1">2) 2b/1
<span class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: 400;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px;color: #1d1d1b;font-family: robotoregular, sans-serif;background-color: #ffffff" role="presentation" data-mathml="2b+4ab1+2a="><span class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: 400;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px;color: #1d1d1b;font-family: robotoregular, sans-serif;background-color: #ffffff" role="presentation" data-mathml="2b+4ab1+2a=">
<span id="MathJax-Element-8-Frame" class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: normal;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px" role="presentation" data-mathml="2b(1+2b)1+2a">3) 2b(1+2b)/1+2a
<span id="MathJax-Element-5-Frame" class="mjx-chtml MathJax_CHTML" style="line-height: 0;text-indent: 0px;text-align: left;text-transform: none;font-style: normal;font-weight: 400;font-size: 19px;letter-spacing: normal;float: none;direction: ltr;max-width: none;max-height: none;min-width: 0px;min-height: 0px;border: 0px;margin: 0px;padding: 1px 0px;color: #1d1d1b;font-family: robotoregular, sans-serif;background-color: #ffffff" role="presentation" data-mathml="2b+4ab1+2a=">