Question

Find
(2.2 x 107)(5 x 108)
(2.5 x 103)(8.8 x 105)
expressed in scientific notation.
A) 2.0 x 106
B) 2.0 x 107
C) 5.0 x 105
D) 5.0 x 106

Answer 1

Answer:

  D)  5.0×10^6

Step-by-step explanation:

Judging by the answer choices, it looks like you want the value of ...

  $\dfrac{(2.2\cdot 10^7)(5\cdot 10^8)}{(2.5\cdot 10^3)(8.8\cdot 10^5)}=\dfrac{2.2(2\cdot 2.5)}{2.5(2.2\cdot 4)}\cdot 10^{7+8-3-5}\\\\=0.5\cdot 10^7=\boxed{5\cdot 10^6}$

Common factors in numerator and denominator cancel, and the usual rules of exponents apply.

  (a^b)(a^c) = a^(b+c)

  1/a^b = a^-b

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Of course 2/4 = 1/2 = 0.5 = 5×(1/10) = 5×10^-1.