Question

4200 and 2100 simplified to there lowest terms

Answer 1

4000 for 4200
2000 for 2100

(If you meant a different answer please explain)

Answer 2

4,200 and 2,100 rounded to the nearest thousand...

4,200 = 4,000

2,100 = 2,000

Hope this helps

-AaronWiseIsBae