I need help on an algera problem

Logically this is very simple

you need to have more than 6000 point left over: the smallest answer over 600 is 6001

And you want to redeem 2350 points: therefore you need to add the two

6001+2350=8351 . to check your answer work back.

go into the store with 8351. Spend 2350. that leaves 6001 which is over 6000. Of course any number over this will work.