Question

Choose one of the factors of x3 + 343

Answer 1

If we observe closely the given, we can note that the terms given are perfect cubes. That is,

            x^3 is cube of x     and

            343 is cube of 7

 

Hence, the expression is the sum of two cubes. For the sum of cubes, we follow the following rule for the factoring:

                            a^3 + b^3 = (a + b)(a^2 – ab + b^2)

 

Applying the rule to the given, the factors would be:

                            X^3 + 373 = (x + 7)(x^2 – 7x + 49)