PLEASE help me Explain each step too in how u got ur answer.

Arectangle plot measure 20ft. by 30ft. a 3-ft.-wide sidewalk surrounds it. find the area of the sidewalk.

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?

35 ! insert < , > , or = to make the sentence true. 12 __ 25 > =