Question 240343
The formula for the area of a rectangle is:  Area = width*lenght
.
Let width = x
and lenght = x + 6
Area = 55 square cm
.
{{{x(x+6)=55}}}
{{{x^2+6x=55}}}
{{{x^2+6x-55=0}}}
{{{(x+11)(x-5)=0}}}
{{{x=-11}}} or {{{x=5}}}
.
Check:
{{{x(x+6)=55}}}
{{{-11(-11+6)=55}}}
{{{-11(-5)=55}}}
{{{55=55}}}
.
{{{x(x+6)=55}}}
{{{5(5+6)=55}}}
{{{5*11=55}}}
{{{55=55}}}
.
*** Even though both numbers check, the width of a rectangle (or its lenght for that matter) must be a positive number, so we choose {{{x=5}}} ***