Which of the following are square roots of the number below? check all that apply.

400

a. 400 1/2

b. -400 1/2

c. 10

d. 20

e. 40

f. -20

Can someone me and do the problem plz so i can understand it more better

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?