Which of the following is a factor of x3 + 343?
a: x − 7
b: x2 − 14x + 49
c: x2 + 7x + 49
d: x + 7

The factor of x³ + 343 is (x + 7). Option D is correct.

A factor of an expression is usually referred to as a number or an algebraic expression that divides the known expression.

The above algebraic expression needs to be expanded to determine its factor;

Mathematically;

Therefore, we can conclude that the factors are (x + 7) (x² - 7x + 49)    

Learn more about factors of a polynomial here:

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x + 7

Step-by-step explanation:

Since both terms are perfect cubes, factor using the sum of cubes formula, where a = x and b = 7

(x + 7) (x - 7x + 49)