Question 47008
width = w
length = 8w + 2
{{{AREA = lw}}}
{{{210 = 8w^2 + 2w}}}
{{{0 = 8w^2 + 2w - 210}}}
{{{0 = 4w^2 + w - 105}}}
{{{0 = 4w^2 + 21w - 20w - 105}}}
{{{0 = (4w^2 + 21w) + (-20w - 105)}}}
{{{0 = w(4w + 21) - 5(4w + 21)}}}
{{{0 = (w - 5)(4w + 21)}}}
Since a measure ment can not be negative, your width is:
w - 5 = 0
w = 5
length = 8w + 2 = 42