Question

The length of a hall is 5m more than its breadth. If the area of the floor of the hall is 84m^2 , what are the length and breadth of the hall?​

Answer 1

Answer: Length = 12, Breadth = 7

Step-by-step explanation:

Let l be the length and b be the breadth, Thus l x b = 84

We are given that length is 5 more than breadth OR l = b + 5

(b + 5) x (b) = 84

b^2 + 5b - 84 = 0

b^2 + 5b + (7b - 7b) - 84 = 0

b^2 + 12b -7b - 84 = 0

b ( b + 12 ) -7 ( b + 12 ) = 0

( b - 7 ) ( b + 12 ) = 0

b - 7 = 0 and b + 12 = 0

b = 7 and b = -12

Since breadth is a length it cannot be negative. So, b = 7 and l = 12

Answer 2

Hey Buddy...

Step-by-step explanation:

Let the breadth of the hall be ‘a’

Length = a + 5

Given, area of the floor of the hall is 84 m2

⇒ a(a + 5) = 84

⇒ a2 + 5a – 84 = 0

⇒ a2 + 12a – 7a – 84 = 0

⇒ a(a + 12) – 7(a + 12) = 0

⇒ (a – 7)(a + 12) = 0

⇒ a = 7 m

Length of the hall = 7 + 5 = 12 m.

Hope this helps u dude