Amir wants to buy a video game that costs $70 but he only has $20. He can earn $10 for each car he washes. How many cats he must wash to have enough money to buy the game?

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm