You have ​$80 in your bank account. Each week you plan to deposit ​$8 from your allowance and ​$15 from your paycheck. The equation bequals80plus​(15plus8​)w gives the amount b in your account after w weeks. How many weeks from now will you have ​$240 in your bank​ account?

1 answer

To find out how many weeks \( w \) it will take to have \( $240 \) in your bank account, we can start with the equation you provided:

\[ b = 80 + (15 + 8)w \]

First, simplify the equation:

\[ b = 80 + 23w \]

Now, we want to find \( w \) when \( b = 240 \):

\[ 240 = 80 + 23w \]

Next, subtract \( 80 \) from both sides:

\[ 240 - 80 = 23w \]

\[ 160 = 23w \]

Now, divide both sides by \( 23 \):

\[ w = \frac{160}{23} \approx 6.96 \]

Since \( w \) represents the number of weeks, you will need to round up because you cannot have a fraction of a week. Therefore, it will take approximately \( 7 \) weeks to have at least \( $240 \) in your bank account.