If (4.2)x = (0.42)y = 100, then (1/x) - (1/y) =  Choose one:	A) 1	B) 2	C) 1/2	D) 1/4	E) 2
(4.2)x = 100   =&gt; (42)x = 102+x   =&gt; 42 = 10(2/x+1) ---------- (i)   [42/100]y = 100 =&gt; 42y = 102+2y   =&gt; 42 = 102/y+2-------- (ii)   From (i) and (ii), 2/x - 2/y = 1   =&gt;1/x - 1/y = 1/2.   ANSWER:1/2
<result>C</result>
If (4.2)x = (0.42)y = 100, then (1/x) - (1/y) =