College Algebra (6th Edition)

$3\times10^{-8}$
$$\frac{7.5\times10^{-2}}{2.5\times10^{6}}$$ Regroup like terms then simplify $$=(\frac{7.5}{2.5})(\frac{10^{-2}}{10^{6}})$$ When dividing exponential expressions with the same non-zero base, subtract the exponent of the denominator from the exponent of the numerator. $$=3\times10^{(-2-6)}$$ $$=3\times10^{-8}$$