What is the equivalent to square root of -100

Susie wants to take her friend out for lunch.she wants to spend $9.75 each person. how much will she spend in all.

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?

What is 74 round to the nearest ten