If 5 + 7/X = 6 - 5/X, then X =
Answers:
A) 7
B) 14
C) 12
D) 6/7
E) 5
We're given the equation 5 + 7/X = 6 - 5/X. We're asked for the value of X.   The common-denominator of these 4 numbers is X, so we need to multiply both sides of the equation by X, giving us...   5X + 7X/X = 6X - 5X/X   We can then eliminate that denominator, which gives us....   5X + 7 = 6X - 5   12 = X   12
<result>C</result>
If 5 + 7/X = 6 - 5/X, then X =