Question

The factorization of 8x3 – 125 is (2x – 5)(jx2 + kx + 25). What are the values of j and k

Answer 1

`j=4\\k=10`

Explanation:

`8x^3 - 125`

`\left(2x\right)^3-5^3`

Use this formula:

`x^3-y^3=\left(x-y\right)\left(x^2+xy+y^2\right)`

Where,

`x=2x\\y=5`

Substitute in the values.

`\left(2x\right)^3-5^3=\left(2x-5\right)\left(2^2x^2+5\cdot \:2x+5^2\right)`

`\left(2x-5\right)\left(4x^2+10x+25\right)`