In this question, it is given that
Leanne has a gas card that has $150 on it. She spends $25 a week on gas.
And we have to Write a recursive rule that represents the amount of money she has on her gas card after the first week .
Recursive rule shows the relationship between previous value and the current value .
And here, the recursive rule is

Where a(n-1) is the initial amount which is $150 . And a(n) is the amount after n week .
So for n=1, that is amount in the card after 1 week, we will get

And that's the amount remaining in the card after 1 week .