There are 624 students at lincoln middle school. 78 of the students are left-handed. what percent of students at lincoln middle school are left-handed? !

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