Which equation can be used to find the perimeter of a regular decagon with sides of length 5 m?

p = 10 + 5

p = 10 5

p = 2(5) + 2(10)

p = 10(5)

Consider u = {x|x is a negative real number}which is an empty set? o {x|x eu and x has a negative cube root}o {x|x eu and x has a negative square root}{x|x eu and x is equal to the product of a positive number and -1}{x|x eu and x is equal to the sum of one negative and one positive number?