What’s the opposite of the number of -13

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.

At $1.32 million, they closed last month percent above what they paid in 2007." how much did they pay in 2007?

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?