if log10 7 = a then log10 (1/70) equal to  Select:
A) -(1+a)	B) (1+a)	C) (1+2a)	D) (2+a)	E) (2+2a)
log10(1/70) = log10 1 - log10 70   = - log10 (7*10)   = -(log10 7 + log10 10) = -(a+1)   -(1+a)NSWER -(1+a)
<result>A</result>
if log10 7 = a then log10 (1/70) equal to