Question

18. The breadth of a rectangle is 4 cm less than its length. If the length is increased by 4 cm and the
breadth is decreased by 1 cm, the area of the rectangle is increased by 40 cmsq. Find the length and
breadth of the rectangle.​

Answer 1

Answer:

Length = 10cm

Breadth = 6cm

Step-by-step explanation:

Let Length of rectangle be x

Then, the breadth will be x-4

So, area = x(x-4) = x^2 - x

Now, The new length is x+4 and the new breadth is x-5

So, are = (x+4)(x+5) = x^2 + 9x + 20

It is given that new area is greater than the old are by 40cm^2

So,

(x^2 + 9x + 20) - (x^2 - x) = 40

x^2 + 9x + 20 - x^2 + x = 40

10x + 20 = 40

10x = 20

x = 10 [Length is 10cm]

x-4 = 6 [Breadth is 6cm]

Hope it helps (:

Please mark it as the brainliest answer (: