You might be able to by booting the chromebook up on developer mode. However, this is risky and don't say I didn't warn you. You could potentially factory reset the chromebook.

B send me your paypal. ill give you some money to buy a pc..

hi

if you factory reset a Chromebook which is shool issued it will keep your data at the school web

I will offer an official answer: You Can Not. It is not possible. The school has restrictions that block these tools, so you cannot use them. For me, they are also greyed out, which is why I have to rely on the repl console and try/catch method to give me errors. This is also why control shift i will not work. On the other hand, there is a bookmarklet that can give the effect of inspect element, which uses firefox XRay:

javascript:(function() {
var script=document.createElement('script');
script.src='https://goggles.mozilla.org'+'/webxray.js';
script.className='webxray';
script.setAttribute('data-lang','en-US');
script.setAttribute('data-baseuri','https://goggles.mozilla.org');
document.body.appendChild(script);}())

OR

javascript:(function(){var script=document.createElement('script');script.src='http://webxray.toolness.org/webxray.js';script.className='webxray';document.head.appendChild(script);})();

OR

javascript:(function() {var s = document.createElement('script');s.type='text/javascript';document.body.appendChild(s);s.src='http://webxray.toolness.org/webxray.js';void(0);})();

-> See, it's greyed out
You can mark my answer as the correct one :D so we can close this post out.

I would strongly advise against it.

could i possibly open dev tools using a repl? if so what code should I input?

Actually, try CTRL+ALT+T to open crosh and copy, rename and run the devtools package from there.

You cannot, easily anyway, there is a way.
What do you want to do with the dev tools?

There used to be a bookmarklet called Firebug, but I'm pretty sure they terminated the project and canceled any further updates.