Question 123943
Start with the formula for the perimeter of a rectangle:
{{{P = 2L+2W}}}
You are given that the width (W) is 3 meters less than the length, L, so W = L-3. You are also given the perimeter, P = 14 meters. Making the appropriate substitutions into the formula, you'll get:
{{{14 = 2L + 2(L-3)}}} Simplify and solve for L
{{{14 = 2L + 2L - 6}}} Combine like-terms.
{{{14 = 4L-6}}} Add 6 to both sides.
{{{20 = 4L}}} Divide both sides by 4.
{{{5 = L}}} The length is 5 meters.
{{{W = L-3}}}
{{{W = 5-3}}}
{{{W = 2}}}meters.
The width is 2 meters. 
Check:
{{{P = 2L+2W}}}
{{{P = 2(5)+2(2)}}}
{{{P = 10+4}}}
{{{P = 14}}}meters.