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
![a_(n) = a_(n-1)-25n](https://img.qammunity.org/2019/formulas/mathematics/middle-school/v80tq2itkg39tmhb3wqhsyjsm7pqj17a5g.png)
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
![a_(1) = a_(1-1) -25(1) \\ a_(1) = a_(0) -25 \\ a_(1) = 150 -25 \\ a_(1) = $125](https://img.qammunity.org/2019/formulas/mathematics/middle-school/n1vl9ffpcs3jd7uzjs2k27bd485rzedu12.png)
And that's the amount remaining in the card after 1 week .