How to interpret an expression with function notation | Functions | Algebra I | Khan Academy

TL;DR

The statement "M of 30 minus M of 0 equals a hundred" means that the account balance after 30 days is a hundred dollars more than the initial balance.

Transcript

Arjun opened up a savings account last year and put an initial sum in it. Let M of t denote the account balance M measured in dollars t days since it was opened. What does the statement M of 30 minus M of 0 equalling a hundred mean? Before I look at the choices, let's think about what this means. When you input t equals 30 into your function, you'r... Read More

Key Insights

• ⚖️ The equation represents the difference between the account balance after 30 days and the initial balance.
• 🥳 Interpreting the equation depends on whether the balance after 30 days is seen as a hundred dollars more than the initial balance or as an addition of a hundred dollars in the initial 30 days.
• ❓ It is not stated whether the equation refers to a profit or interest earned on the account.
• ⚖️ The equation rules out interpretations like the balance after 30 days being exactly a hundred dollars or the initial balance being equal to the balance after 30 days.
• 🥳 The equation suggests that the account balance increased by a hundred dollars within the first 30 days.
• 🥳 The interpretation of the equation depends on the perspective of either balance difference or added amount within the first 30 days.
• ⚖️ Arjun's account balance could have increased due to interest or other types of profit.

Questions & Answers

Q: What does the equation "M of 30 minus M of 0 equals a hundred" represent?

The equation represents the difference between the account balance after 30 days and the initial balance, where the difference is equal to a hundred dollars.

Q: How can the equation be interpreted in terms of the account balance?

The equation can be interpreted as the balance after 30 days being a hundred dollars more than the initial balance or as adding a hundred dollars in the first 30 days.

Q: Could the equation mean that the balance after 30 days is exactly a hundred dollars?

No, the equation does not imply that the balance after 30 days is exactly a hundred dollars. It represents the difference between the two balances being equal to a hundred dollars.

Q: Is it possible for the initial balance to be higher than the balance after 30 days?

No, based on the equation, the initial balance should be subtracted from the balance after 30 days, resulting in a positive difference of a hundred dollars.

Summary & Key Takeaways

• Arjun opened a savings account and wants to interpret the meaning of the equation "M of 30 minus M of 0 equals a hundred."

• The equation represents the difference between the account balance 30 days after opening and the initial balance.

• Possible interpretations include the balance after 30 days being a hundred dollars more than the initial balance or adding a hundred dollars in the first 30 days.