Cannot understand the sum .please explain it (8 + Jitj)y units.
Perimeter of A AEC : perimeter of trap. ABEC (4 + ) : (8 +
Example 17 II' the length ofa rectangle is increased by 10 cm and the breadth by
5 Cln, the area is unaltered. If the length is chq Teased by and Increased
by 4 cm, even then the area is unaltered.
Find the ('f the
Solution. Let the length and the breadth Of the rectangle be x cm and y cm respectively,
then its area = xy cm .
According to the first condition of the question, when length is increased by 10 cm and
breadth decreased by 5 cm, area of the rectangle remains unaltered.
(x + 10) (y — 5) = xy
xy —5x + I Oy — 50 = xy
-5x+ loy -50 = o
x — 2Y+ 10 = O
According to the second condition of the question, we get
(x — 5) (y + 4) = xy
xy +4x — 5y — 20 = xy
Multiplying (i) by 4, we get
Subtracting (iii) from (it), we get
3y — 60 = 0 3y = 60 y = 20.
From we get
x-2x20+10=o 10=0 —x = 30.
Hence the length of the rectangle = 30 cm and its breadth = 20 cm.
plenf The side of a square exceeds the side of another square by 3_cm and the s
of the areas of the two squares is 549 cm2. Find the perimeters of the squares.