The perimeter of a parallelogram is 140 cm. If one of the sides is longer than the other by 10 cm, find the length of each of its sides.
Let x be the common multiple.
According to question, sides will be x and (x + 10).
Perimeter = 
140 = 2 (x + (x + 10))
140 = 2 (2x + 10)
140 = 4x + 20
4x = 120
X =30 cm
X + 10 = 40 cm
So, sides will be 30 cm and 40 cm.
7