Answer
$4.3 \times 10^4$
Work Step by Step
RECALL:
(i) $(a^m)^n = a^{mn}$
(ii) $(ab)^m=a^mb^m$
(iii) $a^m \cdot a^n =a^{m+n}$
(iv) $a^0=1, a\ne0$
(v) $a^{-m} = \dfrac{1}{a^m}$
Use rule (i) above to obtain:
$=10^{3\cdot4} (4.3 \times 10^{-8})
\\=10^{12} (4.3 \times 10^{-8})$
Use rule (iii) above to obtain:
$=4.3 \times 10^{12+(-8)}
\\=4.3 \times 10^4$