(2 x 10^4) x (4 x 10^5=?

(2*10^4)x(4*10^5) is the exact same as (2*4)*(10^4*10^5) due to the associative property Obviously 2*4 = 8 When multiplying exponents you add them so... 10^4*10^5 = 10^(5+4) = 10^9 Your answer is then simply 8*10^9 and in the form your question is asking
for it will be 8 with 9 zeros, I'm adding the spaces for visual clarity 8 000 000 000 In numeric terms its 8 billion. Apologies for the block of text, the website appears to be having an issue right now and won't display the answer as typed out.