Corey and Courtney are 210 feet apart when they start walking toward one another. Courtney walks twice as fast as Corey so whenever Corey travels
x
feet, Courtney travels
2
x
feet. Let
x
represent the number of feet Corey has traveled since he started walking toward Courtney.
Write an expression in terms of x to represent the distance (in feet) between Corey and Courtney.