Question

Which of the following is a factor of 8 – 125x3?

2 + 5x

4 + 20x + 25x2

4 + 10x + 25x2

None of the above

Answer 1

Use this:

\[a^3 - b^3 = (a-b)(a^2 + b^2 + ab)\]

Answer 2

You can write the above expression as:

\[2^3 - (5x)^3\]

Now use the above formula..

Answer 3

First - express it as \(2^3 - (5x)^3\)

\(\Rightarrow a^3 - b^3 = (a - b)(a^2 + ab + b^2) \Longrightarrow 2^3 - (5x)^3 = (2 - 5x)(4 + 10x + 25x^2)\)

Answer 4

@ waterineyes is it 4 + 10x + 25x2

Answer 5

Yes..

Answer 6

But the entire is:
\[(2−5x)(4+10x+25x^2)\]