Question

The length of her rectangle is greater than the breadth by 18 centimeter. If both length and breadth are increased by 6cm, then the area increases by 168 centimeter square. Find a length and breadth of the rectangle.

Answer 1

Let the length of the rectangle be x cm and the breadth be y cm.
area of the rectangle = x * y = xy sq.cm
x = y + 18 ..........1 st equation.

and,
[ x + 6 ] * [y + 6] = xy + 168
xy + 6x + 6y + 36 = xy + 168
6x + 6y = 132

now substituting value of x here,

6 [ y + 18 ] + 6y = 132
6y + 108 + 6y = 132
12y = 24
y= 2  cm = breadth 

length = x = y + 18 = 18 + 2 = 20 cm.