To solve the binomial equation, we'll apply the identity
of the sum of cubes:
a^3 + b^3 = (a+b)(a^2 - ab +
b^2)
a^3 =216x^3
a =
6x
b^3 = 13^3
b =
13
216x^3+2197 = (6x+13)(36x^2 - 78x +
169)
If 216x^3+2197 = 0, then (6x+13)(36x^2 - 78x + 169) =
0
If a product is zero, then each factor could be
zero.
6x+13 = 0
We'll
subtract 13 both sides:
6x =
-13
x1 = -13/6
36x^2 - 78x +
169 = 0
We'll apply the quadratic
formula:
x2 = [78 +
sqrt(6084-24336)]/72
x2 =
(78+i*sqrt18252)/72
We'll factorize by 78 the
numerator:
x2 = (78+78i*sqrt
3)/72
x2 = 13(1+isqrt3)/12
x3
= 13(1-isqrt3)/12
The roots of the equation
are: {-13/6 , 13(1+isqrt3)/12, 13(1-isqrt3)/12}.
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