Question

At the beginning of the month Khalid had $25 in his school cafeteria account. Use a variable to

represent the unknown quantity in each transaction below and write an equation to represent
it. Then, solve each equation. Please show ALL your work.
1. In the first week he spent $10 on lunches: How much was in his account then?
There was 15 dollars in his account
2. Khalid deposited some money in his account and his account balance was $30. How
much did he deposit?
he deposited $15
3. Then he spent $45 on lunches the next week. How much was in his account?

Answer 1

Let's denote the unknown quantity (amount in the account after the first week) as 'x'.

Given:

Account balance at the beginning of the month = $25

Amount spent on lunches in the first week = $10

1 - Equation: Account balance at the beginning - Amount spent = Amount in the account after the first week

x = $25 - $10

To solve the equation:

x = $15

Therefore, after the first week, there was $15 in Khalid's account.

2- Equation: Account balance after the deposit - Account balance before the deposit = Amount deposited

$30 - $15 = x

To solve the equation:

$15 = x

Therefore, Khalid deposited $15 into his account.

3- Equation: Account balance after the first transaction - Amount spent = Amount in the account after the second transaction

x = $30 - $45

To solve the equation:

x = -$15

The result is -$15, which implies that Khalid's account was overdrawn by $15 after spending $45 on lunches in the next week.