(X^3-4x)(x^2+2x-8)(x^2+7x+10)

(х^3-4x)(x^2+2x-8)(x^2+7x+10) =
х(х^2-4)(х^4+7х^3+10х^2+2х^3+14х^2+20х-8х^2-56х-80) =
х(х^2-4)(х^4+9х^3+16х^2-36х-80) =
х(х^6+9х^5+16х^4-36х^3-80х^2-4х^4-36х^3-64х^2+144х+320) =
х(х^6+9х^5+12х^4-72х^3-144х^2+144х+320) =
х^7+9х^6+12х^5-72х^4-144х^3+144х^2+320х.