If log10 7 = a, then log10 (1/70)is equal to: Choose the most appropriate option.
A) - (1 + a)
B) (1 + a)-1
C) a /10
D) 1 /10a
E) None of these
Explanation:   log10 (1/70)= log10 1 - log10 70   = - log10 (7 x 10)   = - (log10 7 + log10 10)   = - (a + 1).   - (1 + a)NSWER IS - (1 + a)
<result>A</result>
If log10 7 = a, then log10 (1/70)is equal to: