Question 31079
SEEING AS THE WOOD COST $.20 PER SQ FOOT THEN HE SAVED A TOTAL OF 13 SQ FEET WITH THE REDUCED TABLE SIZE THEREFORE

X(X+3)=(X-1)(X+1)+13 THIS COMPARES THE ORIGINAL SIZE X WIDE AND (X+3) LONG &
THE REDUCED SIZE OF (X-1) FOR THE WIDTH AND (X+3-2) FOR THE LENGTH 
THUS WE HAVE X~2+3X=X~2-1+13 OR CANCELLING OUT THE X~2 WE ARE LEFT WITH
3X=12 OR X=12/3 OR X=4 
PROOF THE ORIGINAL TABLE WAS 4 BY 7 OR 28 SQ FEET @ .20 SQ FOOT IT COST $5.60
THE REDUCED TABLE OF (4-1) AND (7-2) OR 3 BY 5 OR 15 SQ FEET @$.20 SQ FOOT IT COST $3.00 THERFORE THE SAVINGS WAS $5.60-$3.00=$2.60