Answer:
Grace needs to borrow $23,000 in students loan in order to attend University of Oklahoma for 4 years.
Explanation:
Cost for one year at University of Oklahoma = $20,000
Cost for 4 years = 4 × $20,000 = $80,000
Total amount Grace would have in 4 years = $4,000 + $1,000 + ($4,000×4) + ($9,000×4) = $57,000
Amount she needs to borrow = $80,000 - $57,000 = $23,000