1) [tex]8.4 \times 10^{2} [/tex] is the same as [tex] 8.4 \times 100[/tex] because the order of operations state to perform the exponents before multiplication.
[tex]8.4 \times 100 = 840[/tex]
The answer is C) 840
2) I'm assuming the second thing you said was a typo, but 8.4 × 10*2 is the same as 8.4 x 20, for the same reason above. 8.4 x 20 = 168.
