Question 1008764
The area of a rectangle is:

 {{{A=105cm^2}}}
 If the length is {{{x}}} and the width is {{{(2x+1)}}}, then

{{{x(2x+1)=105}}} 

{{{2x^2+x=105}}} 

{{{2x^2+x-105=0}}} 

{{{2x^2+15x-14x-105=0}}} 

{{{(2x^2-14x)+(15x-105)=0}}}

{{{(2x^2-14x)+(15x-105)=0}}}

{{{2x(x-7)+15(x-7)=0}}}

{{{(x-7)(2x+15) = 0}}}

solutions: we need only positive solution since we are looking for width

if {{{(x-7) = 0}}}=>{{{highlight(x=7)}}}-> the length

and {{{(2x+1)=2*7+1}}}=>{{{highlight((2x+1)=15)}}}->the width