Respuesta :

Answer:

4 times greater

Step-by-step explanation:

[tex]8.4*10^2=840\\2.1*10^2=210\\840/210=4\\[/tex]

Answer:

C. 400 times greater

Step-by-step explanation:

8.4 · [tex]10^{4}[/tex]

84000

2.1 · 10²

210

84000 ÷ 210 = 400

C. 400 times greater