What is the x-coordinate of the solution for the system of equations?

{y−x=9
{10+2x=−2y

enter your answer in the box.
x =

Atotal of 766 tickets were sold for the school play. they were either adult tickets or student tickets. there were 66 more student tickets sold than adult tickets. how many adult tickets were sold?

Simplify the algebraic expression 8y-2(y+4)

The label on a can of lemonade gives the volume as 12 fl 0z or 355ml verify that these two measurements are nearly equivalent