Answer:
12 5/6 inches
Step-by-step explanation:
You want to find the value of L when S=12 1/2, using the formula S = 3L -26.
Foot length
You can substitute for S in the formula before or after you solve for L. Here, we'll solve for L first:
S +26 = 3L . . . . add 26 to both sides
(S +26)/3 = L . . . . divide both sides by 3
Substituting 12 1/2 for S, this becomes ...
L = (12 1/2 +26)/3 = (38 1/2)/3 = (77/2)/3 = 77/6 = 12 5/6
A man's foot is 12 5/6 inches long if he wears a size 12 1/2 shoe.
