Question

Choose one of the factors of x3 − 1331

x-11 (I'm pretty sure its this one but I'm just checking)

x2-11x+121

x2+22x+121

none of the above

Answer 1

Use formula for difference of perfect cubes:

`a^3-b^3=(a-b)(a^2+ab+b^2).`

Consider expression
`x^3-1331.` You know that
`1331=11^3,` then

`x^3-1331=x^3-11^3=(x-11)(x^2+11x+121).`

The quadratic trinomial
`x^2+11x+121` cannot be factored anymore, so the expression
`x^3-1331` has two factors
`x-11` and
`x^2+11x+121.`

Answer: correct choice is A.

Answer 2

Hello,


`a^3-b^3=(a-b)(a^2+ab+b^2)\\ Here\ a=x \ and \ b=11`

x^3-11^3=(x-11)(x²+11x+121)
Answer A
I haven't read the question : x-11 is a factor! sorry.