Question 418611
If operation 'o' is unknown and, a 'o' b = a + 2b ; and, 3 'o' X = 4 ; what is variable X? 
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Assume the operation is multiply 
ab = a + 2b
ab - a = 2b
a(b-1) = 2b
a = {{{(2b)/(b-1)}}}
choose a convenient value for b, find a; b=2
a = {{{(2*2)/(2-1)}}}
a = {{{4/1}}}
a = 4 when b = 2
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Check this: 4 * 2 = 4 + 2(2)
therefore
3x = 4
x = {{{4/3}}}
x = 1{{{1/3}}}
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There are probably other solutions, but this is one