Zombies lose limbs. Mutants grow limbs. Mutant-zombies do both. Today, a certain mutant-zombie grew 55 limbs, lost 1212 limbs, and grew another 22 limbs.

How many limbs does the mutant-zombie have compared to yesterday?

-1135

Step-by-step explanation:

You don't specifically know how many limbs the mutant-zombie had but you know that he grew 55, lost 1212, and then grew another 22. You would calculate the sum of that (-1135) and then add or subtract (in this case subtract) it to however many limbs it had yesterday.