Answer:
After 6 weeks Rosa has saved $490.
Step-by-step explanation:
1. You have the function given in the problem above, where [tex]x[/tex] os the number of weeks:
[tex]f(x)=250+40x[/tex]
2. Therefore, to solve this problem you only need to substitute 6 weeks (or [tex]x=6[/tex]) into the given function, as following:
[tex]f(x)=250+40x\\f(6)=250+40(6)=490[/tex]
3. The result is $490.