Question

the perimeter of a rectangle is 13 cm and its width is 2-3/4 cm find its length

Answer 1

use formula =2(length+ breadth)
breadth=2-3/4=8-3/4=5/4
13=2(length+5/4)
13/2=length+5/4
length= 5/4-13/2=5-26/4=21/4

Answer 2

Perimeter of rect. =2(b+l)
13 =2(11/4+l)
$13= 2( \frac{11 + 4l}{4} )$
$13 = \frac{11 + 4l}{2}$
13*2=11+4l
26=11+4l
26-11=4l
15=4l
$l = \frac{15}{4}$