Question

the length of the rectangle exceed breadth by 9cm. If the breadth and length are increase by 3 cm.the area will be 84cm^2.Find the length and breadth of new rectangle​

Answer 1

Answer:

Step-by-step explanation:

Let the breadth of the rectangle be x cm.  

Then, the length of the rectangle is (x+9) cm.

So, area of rectangle = length x breadth =x(x+9)cm  

2

 

Now, length of new rectangle =(x+9+3) cm =(x+12) cm and

breadth of new rectangle =(x+3) cm.

So, area of new rectangle = length × breadth =(x+12)(x+3)cm  

2

 

According to the given condition,  

(x+12)(x+3)=x(x+9)+84

⇒x  

2

+12x+3x+36=x  

2

+9x+84

⇒15x+36=9x+84

⇒15x−9x=84−36

⇒6x=48

⇒x=8

So, breadth of the rectangle is 8 cm and length  

=8+9=17 cm.

Answer 2

Answer:

Length = 17cm

Breadth = 8cm

Step-by-step explanation:

Let breadth be x

so length will be (x+9)

Area of the rectangle  = x  ×  (x +9) m2

Now if both l and b are increased by 3 cm then

length = (x+3+9) = (x+12)

breadth =(x+3)

It also says that if their l and b are  increased then new area will have 84cm2 added.

So, Area is (x + 12) (x + 3) = x (x + 9) + 84

x2 + 15x + 36 = x2 + 9x + 84

15x – 9x = 84 – 36

6x=48

x=48/6=8

So length = x= 8

So breadth = x+9=17