Aconsists all elements of b if and only if a union b is equal to b

Can someone me i’m confused. will give brainliest and a whole bunch of points

Lv beethoven software supplies customized software to a managed healthcare system. lv beethoven software's costs for the software is $1,723,000. lv beethoven software sells the software to the healthcare system for $3,816,981.10. overhead expenses are estimated at 47% of the selling price. what is lv beethoven software's net profit to the nearest dollar?

How can constraints be used to model a real-world situation?