Which of the following is an arithmetic sequence?

1/2, -1/2, 1/2, -1/2 ...
12, 4, 4/3, 16/3 ...
1/2, -1/2, -3/2, -5/2 ...
2, 4, 8, 16, ...

Which of the following are accepted without proof in a logical system? check all that apply.

How much money does ron have left each month after his fixed expenses? ron graduated from college five years ago. he recently bought a house, but shares it with a housemate who pays him $800 a month for rent and utilities. ron is putting a budget worksheet together so he will have a better idea of where his money is going and where he can save. enlarge

Arectangular lawn is 65 m long and 34 m wide. over time, people have walked along a diagonal as a shortcut and have created a straight path. what is the length of the path, to the nearest tenth of a meter? enter your answer as a deicmal in the box. m