Interest earned after 15 days on $8000, at 8.5%

Solve the system of equations. y= 2x y= x^2 - 15

The rumpart family is building a new room onto their house. the width of the new room will be 16 feet. the length of the room will be 4% greater than the width. write an expression to find the length of the new room. what will be the area of this new room?

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?