How much should an eleven year old boy weigh?

Plz which expression is equivalent to the expression below?

You earn a 12% commission for every car you sell. how much is your commission if you sell a $23,000 car?

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