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D( x )
3-(4*e^7*x) = 0
3-(4*e^7*x) = 0
3-(4*e^7*x) = 0
3-4*e^7*x = 0
3-4*e^7*x = 0 // - 3
-4*e^7*x = -3 // : -4*e^7
x = -3/(-4*e^7)
x in (-oo:-3/(-4*e^7)) U (-3/(-4*e^7):+oo)
1/(3-(4*e^7*x)) = 9 // - 9
1/(3-(4*e^7*x))-9 = 0
1/(3-4*e^7*x)-9 = 0
1/(3-4*e^7*x)+(-9*(3-4*e^7*x))/(3-4*e^7*x) = 0
1-9*(3-4*e^7*x) = 0
36*e^7*x-26 = 0
(36*e^7*x-26)/(3-4*e^7*x) = 0
(36*e^7*x-26)/(3-4*e^7*x) = 0 // * 3-4*e^7*x
36*e^7*x-26 = 0
36*e^7*x-26 = 0 // + 26
36*e^7*x = 26 // : 36*e^7
x = 26/(36*e^7)
x = (13*e^-7)/18
x = (13*e^-7)/18
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