Question 41079
Let x be the uniform width
EQUATION:
(20-2x)(12-2x)=84
{{{4x^2-64x+240=84}}}
{{{4x^2-64x+156=0}}}
{{{x^2-16x+39=0}}}
x=3 or x=13
Hence, the unifrom width is 3 cm.
Paul.