To find out when Michael and Lindsey will have the same amount of money, we can set up equations for the amount of money they have after \( w \) weeks.
For Michael:
- He starts with $20 and saves $5 per week.
- The amount of money Michael has after \( w \) weeks can be expressed as: \[ M(w) = 20 + 5w \]
For Lindsey:
- She starts with $0 and saves $10 per week.
- The amount of money Lindsey has after \( w \) weeks can be expressed as: \[ L(w) = 10w \]
To find when both amounts are equal, we can set the two equations equal to each other: \[ 20 + 5w = 10w \]
Now, solve for \( w \):
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Subtract \( 5w \) from both sides: \[ 20 = 10w - 5w \] \[ 20 = 5w \]
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Now divide both sides by 5: \[ w = \frac{20}{5} = 4 \]
So, it will take 4 weeks for Lindsey and Michael to save the same amount of money.