Question 973923
X - .25X + 12 = 36
X - .25X = 24
.75X = 24
Divide each side by .75
X = 32
.
Prove it:
Larry started with 32 books, sold 1/4 of those (or 8).  That left him with 32-8, or 24.  He bought 12 more.  24+12 = 36.