Atable top is shaped like a rectangle whose perimeter is 64 in. the length is 2 in. more than the width. find the length and the width.
the length is:
the width is:

Start with the original equation (length + width= perimeter)
2l + 2w = P
we know here that the length (l) is 2 more than the width (w), 
from this we can say [w= l+2]
put the new w back into the equation
2l + [l+2] = P
now the equation only has one variable, we can simplify it to
3l + 2 = P
we know (from the given information in the origial problem) that the perimeter is 64. 
3l + 2 = 64
tada, not we solve (subtract 2 from both sides)
3l = 62
(divide by 3)
l = 20.67

the length is 20.67
the width is 18.67
:)