Question

the length of a rectangle is greater than 4 times its breadth by 5cm . If its length is reduced by 2cm and breadth is increased by 2 cm then area of rectangle increases by 36cm^2​

Answer 1

Step-by-step explanation:

If we assume the length & breadth of rectangle as L & B respectively….

Area = L * B

Perimeter = 2( L + B)

As per the condition

L* B = 2( L + B) … This is the function which relates the values of L & B

=> LB = 2L + 2B

=> LB - 2B = 2L

The above relationship concludes that L > 2●● as had this L been 2 or <2, values would be imaginary or negative… So these values are ruled out. The same applicable for the value of B too. B > 2 ●●

EXAMPLE:

If L =3, ………….(1)

=> 3B = 6 + 2B

=> B = 6

If L = 2 ……….(2)

=> 2B = 4 + 2B

=> L = 2 does not satisfy the function..

Similarly, if L = 1 …….(3)

1B = 2 + 2B

=> L = 1 , does not satify the function…

=> L > 2