Answer:
686 crystals.
Step-by-step explanation:
You can set up an algebraic equation to find the answer.
Let x represent the number of crystals Lily uses.
The question is asking how many crystals it will take to raise 6,174 zombies, when each crystal raises 9.
9x = 6174
x = 6174 / 9
x = 686
That means it will take Lily 686 dark power crystals to raise 6,174. That's a lot of dark power!
Hope this helps!