Need with algebra homework! to a box that contained 50 pencils 10 out of which were red several more red pencils were added. now 50% of all pencils in this box are red. how many red pencils were added to the box?

The parabola x= √y-9 opens: a.)up b.)down c.)right d.)left

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?

Two airplanes start at the same place and travel in opposite directions,one at 395 miles per hour and the other at 422 miles per hour. how many hours will it take for the planes to be 2451 miles apart?