Question

the perimeter of a rectangle is 91 cm its lenghth is (2x_1) and breath is (x+9) find its length and breadth

Answer 1

Perimeter of rect. = 91cm

2(l+b) = 91cm

=> 2(2x-1+x+9)=91
=> 2(3x+8)=91
=> 6x+16=91
=> 6x=75
x=12.5cm

Length= 2x-1 = 24cm
Breadth = x+9 = 21.5cm

Answer 2

perimeter of rectangle = 2 (l+b )

length = 2x-1

breadth = x+9

according tot he sum 

2 * (2x-1+x+9) = 91

= 4x -2 + 2x+18 = 91

= 6x +16 = 91
 
= 6x = 91-16

6x = 75

x = 75/6 = 12.5

length = 2*12.5 -1 = 25-1 = 24

breadth = x+9 = 12.5+9 = 21.5cm