Question 80698
Call the width of the strip x
The new length of the rectangle will be {{{12 + 2x}}} because
there's a strip on both sides
The new width will be {{{6+2x}}}
{{{(6+2x)(12+2x) = 160}}}
{{{2*(3+x)*2(6+x) = 160}}}
{{{4*(18 + 9x + x^2) = 160}}}
{{{x^2 + 9x + 18 = 40}}}
{{{x^2 + 9x - 22 = 0}}}
{{{(x-2)(x+11) = 0}}}
Eith {{{x = -11}}} or {{{x = 2}}} Negative x is not allowed, so
{{{x = 2}}} answer
check
{{{(6+2x)(12+2x) = 160}}}
{{{(6+2*2)(12+2*2) = 160}}}
{{{10*16 = 160}}}
OK