Let x be the number of weeks it will take Paul to save enough money to buy the skateboard.
In one week, Paul earns $5, so in x weeks he will earn 5x dollars.
Since he already has $25 saved, the total amount of money he will have after x weeks is:
5x + 25
To be able to buy the skateboard that costs $85, Paul needs to save up an additional:
85 - 25 = 60
Therefore, we can set up the following equation to find the number of weeks it will take Paul to save up enough money:
5x + 25 = 60
Simplifying and solving for x:
5x = 35
x = 7
Therefore, it will take Paul 7 weeks to save up enough money to buy the skateboard.
The equation that describes the number of weeks (w) that it will take Paul to save enough money to buy the skateboard is:
5w + 25 = 85