Answer:
[tex]2.0 \times {10}^{4} [/tex]
Step-by-step explanation:
[tex] \frac{2.8 \times {10}^{7} }{1.4 \times {10}^{3} } \\ 2 \times {10}^{7 - 3} \\ 2 \times {10}^{4} [/tex]