Question

the area of rectangle is 21 cm square. if one side exceeds the other by 4 cm .find the dimension of the rectangle

Answer 1

Let the breadth be x.

Then , A/Q,

Length=4+x

Given that Area of rectangle=21 cm^2

Length×breadth=21

(4+x)x =21

4x+x^2 =21

x^2 +4x-21 =0

$\textbf{By middle term splitting}$

x^2 +(7-3)x-21 =0

x^2 +7x-3x-21=0

x(x+7) -3(x+7) = 0

(x+7)(x-3) =0

x+7=0

x=-7

x-3=0

x=3


Since, the sides cannot be negative, Taking x=3

$\underline{\textbf{So, breadth=3 cm}}$

Length=4+breadth

=4+3

$\underline{\textbf{length=7cm }}$

Answer 2

HELLO!

YUR ANSWER IS ......

AREA OF RECTANGLE = 21cm^2

let one side be x ..

it exceeeds the other side by 4 cm..

so , x-4

AREA OF RECTANGLE = L× B

21 = x (x-4)

21 = x2 - 4x

0 = x2 + 4x -21

BY MIDDLE TERM SPLITTING METHOD...

X2 + 4X -21 = 0

= x2 ( 7x -3x) - 21 = 0

( x + 7) (x- 3) = 0

( x + 7 ) = 0

x= -3

since

X cannot be negative so X is equals to 3 ....

DIMENSIONS = 4 + 3

= 7

ANSWER = 7....

HOPE IT HELPS YOU....

PLSEE MARK IT AS BRAINLIEST.....