1. The problem states that Victor and his friends raised a total of $79.25 over two days. 2. On the second day, they raised $64.25. 3. We want to find the amount $a$ they raised on the first day. 4. The total amount raised over two days is the sum of the amounts from each day, so the equation is: $$a + 64.25 = 79.25$$ 5. To solve for $a$, subtract $64.25$ from both sides: $$a + 64.25 - 64.25 = 79.25 - 64.25$$ 6. Using the cancellation notation: $$a + \cancel{64.25} - \cancel{64.25} = 79.25 - 64.25$$ 7. Simplify the right side: $$a = 15$$ 8. Therefore, Victor and his friends raised $15$ on the first day.