STEPS 1&2:
convert ft. to in. (1 ft. = 12 in.)
table: 3.5 ft. = 42 in.
wall: 13 ft. = 156 in.
STEP 3:
draw a diagram. since the table will be centered, the area on both sides are equal.
STEP 4: write an equation to solve based on diagram, then solve for x.
2x + 42 = 156
2x = 114
x = 57
STEP 5: convert inches back to feet by dividing x by 12
57/12 = 4.75 ft
4 3/4 ft of wall on either side of the table