Question 30430
Let the base be b.
the numbers in the expression can be re-written as,

{{{4 = 4*b^0}}}
{{{12 = 1*b^1 + 2*b^0}}}
{{{103 = 1*b^2 + 0*b^1 + 3*b^0}}}
or,
4 = 4
12 = b + 2
103 = bē + 3
Therefore,
4*(b+2) = (bē+3)
4b + 8 = bē + 3
bē - 4b - 5 = 0
(b+1)(b-5) = 0
b = -1, b = 5
since the base is to  be positivee, then
Ans: b = 5
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