What is the LCM of (8x^3 +80x^2 +200x) and (4x^4+16x^3 - 20x^2)?

⇒ 8x³ + 80x² + 200x = 8x( x² + 10x + 25)

                                = 8x(x + 5)²

and

⇒ 4x⁴ + 16x³ - 20x² = 4x² ( x² + 4x - 5)

                               = 4x² (x + 5) (x - 1)

Now,

The LCM of  8x³ + 80x² + 200x and 4x⁴ + 16x³ - 20x²  = $ 8x^2(x + 5)^2 ( x- 1)$