Use interval notation to indicate the largest set where f is continuous. (If I could get work shown for this it would be great, as I'm trying to figure out how to do this on my own. Thanks!)

Will mark the brainliest. paula makes stained-glass windows and sells them to boutique stores. if her costs total $12,000 per year plus $4 per window for the frame. how many windows must she produce to earn a profit of at least $48,000 in one year if she sells the windows for $28 each?