<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<semantics>
<mrow>
<munder>
<mi>lim</mi>
<mrow>
<mi>x</mi>
<mi>→</mi>
<mn>3</mn>
</mrow>
</munder>
<mfrac>
<mrow>
<mi>x</mi>
<mo stretchy="false">−</mo>
<mn>5</mn>
</mrow>
<mrow>
<msup>
<mi>x</mi>
<mn>3</mn>
</msup>
<mo stretchy="false">−</mo>
<mn>7</mn>
</mrow>
</mfrac>
</mrow>
</semantics>
</math>
Mathbot Says...
I wasn't able to parse your question, but the HE.NET team is hard at work making me smarter.