Answer:D)4 x 10^-10
Explanation:
The given expression is
(5 x 10^-7) (8 x 10^-4)
Firstly, we would multiply the numbers on the left hand side of the 10. It becomes 5 × 8 = 40
Multiplying the 10's, we would apply the law of indices to the powers of 10. It is expressed as
a^2 × a^3 = a^(2 + 3) = a^6
Therefore,
10^-7 × 10^-4 = 10^(- 7 - 4) = 10^ - 11
The simplified form of each expression in scientific notation would be
40 × 10^ -11
= 4 × 10^ -11 +1
= 4 × 10^ -10