Question

ngle.
0. The area of a rectangle decreases by 10 cm?
if the length is decreased by 5 cm and the
breadth is increased by 3 cm. If the length
is increased by 5 cm and the breadth is
increased by 2 cm, then the area increases
by 80 cm?. Find the perimeter of the rectangle.​

Answer 1

Explanation:

Let length be ′a′m

Let length be ′a′mbreadth be ′b′m

Let length be ′a′mbreadth be ′b′marea ′ab′m2

Let length be ′a′mbreadth be ′b′marea ′ab′m2(a+5)(b−3)=ab−5

⇒ab+5b−3a−15=ab−5

⇒5b−3a=10−(1)

(a+3)(b+2)=ab+50

⇒ab+6+3b+2a=ab+50

⇒3b+2a=144−(2)

⇒3b+2a=144−(2)solving equation (1) and (2)

⇒3b+2a=144−(2)solving equation (1) and (2)19b=152

⇒b=152/19=8

5×8−3a=10

⇒3a=40−10=30

⇒3a=30

⇒a=10