I suspect the slab will hold up the tub easily.
If those are the interior dimensions of the tub, your tub will hold 185 gallons of water which weighs around 1500 lbs. 1500 lbs spread over the roughly 12 sqft that your tub touches the floor means you have roughly 125 lbs per square foot or about pound per square inch. If your floor can hold you, it can hold the tub.
Now this is based on logic and some past experience. Someone else may have more experience (and better experience ...) and point out the flaws in my thinking.