Tim and Martha paid $7,900 in qualified employment-related expenses for their three young children who live with them in their household. Martha received $1,800 of dependent care assistance from her employer,which was properly excluded from gross income. The couple had $57,000 of AGI earned equally. What amount of child and dependent care tax credit can they claim on their Form 1040? How would your answer differ (if at all) if the couple had AGI of $36,000 that was earned entirely by Martha?