We can create an equation from the sentence.
"Mikey has a dozen less than five times as many flashcards as Macey."
We can use 'x' for Mikey's cards and 'y' for Macey's.
[tex]\sf x=5y-12[/tex]
Mikey has 238 flashcards, we can plug this in for 'x' in our equation, then solve for 'y' to find out how many flashcards Macey has:
[tex]\sf 238=5y-12[/tex]
Add 12 to both sides:
[tex]\sf 250=5y[/tex]
Divide 5 to both sides:
[tex]\sf y=\boxed{\sf 50}[/tex]
So Macey has 50 flashcards.
