Yeah this is a simple arbitrage opportunity. You want to find the amounts to bet where you have zero risk. So basically you want the payouts in both win-loss cases to be equal. Say X is the amount you bet on the underdog and Y is the amount to bet on the favorite. So then we have the equation 1.12X - Y = Y - X, which solves to a ratio of Y = 1.06X. So for example you bet $106 on the favorite and $100 on the underdog. If the favorite wins, you get $106 - $100 = $6. If the dog wins you get $112 - $106 = $6. So if you bet $530 and $500 you are guaranteed $30 in profit.

PS - Would you mind PM'ing me what matchup and books you are looking at? I'm a small-stakes bettor so I wouldn't affect the lines at all.