The length of a rectangular hall is 5 m more than its breadth. If the area of the hall is 750 m2 then its length is
Given: Length of hall (l) = 5 + breadth(b) = 5 + b
Area of hall = 750 m2
We know that,
Area of rectangle = Length × Breadth
⇒ 750 = (5 + b) × b
⇒ 750 = b2 + 5b
⇒ b2 + 5b – 750 = 0
⇒ b2 + 30b – 25b – 750 = 0
⇒ b(b + 30) – 25(b + 30) = 0
⇒ (b + 30) (b – 25) = 0
This gives us two equations,
i. b + 30 = 0
⇒ b = -30
ii. b – 25 = 0
⇒ b = 25
Since, the length of the rectangle cannot be negative
Therefore, b = 25 m
⇒ l = (b + 5) m
⇒ l = (25 + 5) m
⇒ l = 30 m