The equation would be
x - 18 = collection left
X = how much was your collection before you gave your brother 13 cards
Since we don't know how big was your collection before, this would be the equation to solve it.
Answer:
The answer is [tex]C-18[/tex]
Step-by-step explanation:
In order to determine the answer, we have to build the expression that represents the remain collection.
According to the statement, we do not know the initial collection, but we can express this amount with a variable:
C=initial collection cards
Then, we know that we have to give 18 card to the little brother, so we have to subtract 18 to the initial collection.
The expression for the remain cards is:
[tex]C-18[/tex]
