Question

A rectangle is (9x+3) cm long and (4x+5) cm broad. Find its area

Answer 1

Area of rectangle =l×b

(9x+3)(4x+5)

=9x (4x+5)+3 (4x+5)

=36x^2+45x+12x+15

=36x^2+57x+15

Answer 2

Since area of rectangle= length x breadth

here it would be
$(9x + 3) \times (4x + 5)$
further calculations will be
$= 9x \times (4x + 5) + 3 \times (4x + 5) \\ = (36 {x}^{2} + 45x) + (12x + 15) \\ = 36 {x}^{2} + 57x + 15$
That's the final answer.! Because we cannot simplify it further since 57 is a prime number. Also don't forget the unit at the end.