keynote exporting bug when inserting systems of quadratic equations

Here is another alternative, if you still want to use Powerpoint to run the presentation.

You can install LaTeXiT, which is a long time free application. You can just type a formula,

“\begin{cases}x=t(y+2) \\ x^{2}+2 y^{2}=4\end{cases}”

into LaTeXiT, press the "LaTeXiT" button and it will typeset it, then you can drag the resulting image to Keynote.

Here is what I have discovered using Pages v14.4 and Keynote v14.4 with Word and Keynote v16.103.3.

I can create your equation in Pages and directly copy/paste it into Powerpoint with the equation surviving intact. Entering the same equation in Keynote's equation editor delivers an empty equation box when copy/pasting directly to PowerPoint.

I can copy/paste the Keynote equation into Powerpoint, but the paste operation must be Paste Special and choosing PDF for the equation insertion That preserves the original equation format. No Keynote equation survives export to and opening in PowerPoint.

You can enter this MathML equation syntax in the Keynote equation editor and it will export and open in PowerPoint, though the '=' alignment will be off with the equation in PowerPoint. So it would appear the only solution is to copy/Paste Special of the equation between Apple applications and Microsoft documents.

<math display="block">
 <mfenced open="{" close="">
  <mtable columnalign="right left">
    <mtr>
      <mtd>
        <mi>x</mi>
      </mtd>
      <mtd>
        <mo>=</mo>
        <mi>t(</mi>
        <mi>y</mi>
        <mo>+</mo>
        <mi>4)</mi>
      </mtd>
    </mtr>
    <mtr>
      <mtd>
      <msup>
        <mi>x</mi>
        <mo>2</mo>
      </msup>
      <mo>+</mo>
      <msup>
      <mi>2y</mi>
      <mo>2</mo>
      </msup>
      </mtd>
      <mtd>
        <mo>=</mo>
        <mi>4</mi>
      </mtd>
   </mtr>
  </mtable>
 </mfenced>
</math>

This hasn't anything to do with Keynote or PowerJoint, but I know you have MacTeX installed (a prerequisite for the following extension). Here is how you convert LaTeX source pasted into LibreOffice Writer to an equation object:

1. Install the TexMaths extension into LibreOffice Writer
2. Copy and paste LaTeX source from the OP's contribution above, an Apple application's equation editor, or other source into LibreOffice Writer.
3. Select that source text and from the LibreOffice Writer Tools menu, select TexMaths > Equations…
   1. That LaTeX source is instantly converted into an equation object.

You are welcome. I neglected to mention that equations in MS Word documents only produce a blank object box in LO because MS stores the equations as PDFs and LO isn't equipped to just show that content.

So, one removes the LO blank equation object box, and performs the steps I mentioned.

Thanks, VikingOSX.

I tried this, and got the same result. Powerpoint said there was an error, and "repaired" it by removing the equation completely.

If you cannot use Keynote in the classroom, then an alternative would be to export as pdf and use that instead.

You may lose some animations, but otherwise the slides will be just fine.