Question

Section D
1Q X 4M = 4
10) Rahul has a rectangular garden, with dimensions (2a+7) units and (2a+4) units.
At the centre of the garden, he has left a square shaped place for fountain of
side(9+a) units. In rest of the area he has planned to put artificial green grass. Find
the area of green grass. (solve using the concept of identity.)
(2a+7) units
(2a+4) units
(9+)units​

Answer 1

Answer:

3a²+4a-53unit²

Step-by-step explanation:

area of garden (rectangular garden)= (length×breadth)unit²

= (2a+7)×(2a+4)unit²

= (2a(2a+4)+7(2a+4))unit²

= (4a²+8a+14a+28)unit²

area of fountain (square fountain)=(9+a)² unit²

=(9(9+a)+a(9+a)) unit²

=(81+9a+9a+a²) unit²

area of grass = (4a²+8a+14a+28)-(81+9a+9a+a²) unit²

= 3a²+4a-53 unit²