Question

for what value of x the perimeter of the rectangle with length 5 (X + 6) cm bread th (2x+6)cm will be 192.
the answer should be 8​

Answer 1

$\boxed{*\: Perimeter\:of\:rectangle\:=\:2(l\: +\:b)}$

» The perimeter of the rectangle with length 5(x + 6) cm bread th (2x+6)cm will be 192.

Here..

Perimeter of rectangle = 192 cm

Length (l) = 5(x + 6) cm

=> (5x + 30) cm

Breadth (b) = (2x + 6) cm

__________ [ GIVEN ]

• We have to find the value of x.

_____________________________

Now..

Put the given value in above formula.

Perimeter = 2(5x + 30 + 2x + 6)

=> 192 = 2(7x + 36)

=> 192/2 = 7x + 36

=> 96 = 7x + 36

=> 96 - 36 = 7x

=> 60 = 7x

=> 7x = 60

=> x = 60/7

=> x = 8

_____________________________

x = 8 or 60/7 cm

__________ [ ANSWER ]

______________________________

Answer 2

Perimeter of rectangle = 192 cm

Length = 5(x + 6) = (5x + 30) cm

Breadth = (2x + 6) cm

Perimeter = 2(l + b)

192 = 2(5x + 30 + 2x + 6)

2(7x + 36) = 192

14x + 72 = 192

14x = 120

x = 8 cm