Answer: Mike started with 75 cards
Step-by-step explanation:
Hi, to answer this question we have to write an equation:
The number of cards mike started with (x) plus the new cards added (7) must be divided by 2 (since his dog ate half of his collection).
That expression must be equal to the number of cards left (41)
Mathematically speaking:
(x + 7) /2 = 41
Solving for x:
x+7 = 41x2
x+7 = 82
x = 82-7
x = 75 cards
Feel free to ask for more if needed or if you did not understand something.