Question

If a rectangle has length (4x + 5) and width (2x-3) whose circumference is 40 cm, what is its area?

answer?
class 5th
subject mathematics ​

Answer 1

Answer:

-120

Step-by-step explanation:

(4*+5)*(2*-3)

20*(-6)

-120

Answer 2

Answer:

If a rectangle has the length (4x + 5) and width (2x-3) whose circumference is 40 cm, its area is $51cm^{2}$

Step-by-step explanation:

The circumference of a rectangle is the total linear distance along its boundary

if the length of the rectangle is represented as $l$ and breadth $b$ as shown in the figure then the circumference is equal to $2l+2b$

From the question, it is given that

the length of the rectangle is $l=(4x+5)$

and the breadth is $b=(2x-3)$

therefore the circumference is $=2(4x+5)+2(2x-3)=12x+4$

but circumference is $40cm$

⇒

$12x+4=40\\12x=36\\x=36/12=3cm$

substitute the value of x in length and breadth, we get

$l=(4*3+5)=17cm\\b=(2*3-3)=3cm$

the area of a rectangle is $A=l*b$

$A=17*3=51cm^{2}$