Question 1056345
 (5×10^7)(9×10^3)/4×10^7 = [5*9/4][10*7*10^3/10^7] = 11.25*10*3
= 1.125*10^4
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(5×10^4)(9×10^−7)/1.5×10^−8 = [5*9/1.5][10^4*10^-7/10^-8] = 30*10^5
= 3.0*10^6
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6×10^15/4×10^13 = [6/4][10^2] = 1.5*10^2  
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Cheers,
Stan H.
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