Question 495496
When the fence is finished, its perimeter (P) will be 480 feet.
The formula for the perimeter of a rectangle is:
{{{P = 2(L+W)}}} The length {{{L = W+30}}} and W is the width, so...
{{{480 = 2((W+30)+W)}}} Simplify and solve for W.
{{{480 = 2(2W+30)}}} Divide both sides by 2.
{{{240 = 2W+30}}} Subtract 30 from both sides.
{{{210 = 2W}}} Divide by 2.
{{{W = 105}}}feet, and...
{{{L = W+30}}}
{{{L = 105+30}}}
{{{L = 135}}}feet.
Check:{{{P = 2(L+W)}}}
{{{480 = 2(135+105)}}}
{{{480 = 2(240)}}}
{{{480 = 480}}} OK!