Factor the sum of two cubes x^3+343?

Answer 1

*Use the sum of cubes formula which is >>>

(a + b)(a^2 - ab + b^2)

First: express the terms in lowest terms...

(x)(x)(x) + (7)(7)(7)

Sec: you have two variables...
a = x
b = 7

Third: replace the terms with their corresponding variables...

(x + 7)(x^2 - x(7) + 7^2)

(x + 7)(x^2 - 7x + 7*7)

(x + 7)(x^2 - 7x + 49)

Answer 2

x^3=-343 so x= -7 so x^3+343 = (x+7)(x^2-7x +49)

Answer 3

(x+7)(x^2 - 7x + 49)
343 = 7^3
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http://www.purplemath.com/modules/specfact2.htm
it explains all this stuff.
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