(a+3b)^2-(3a-b)^2=(a+3b-3a+b)(a+3b+3a-b)=(4b-2a)(4a+2b)=4(2b-a)(2a+b)
5a - 5b + b² - ab = 5(a - b) - b(a - b) = (a - b)(5 - b)
(4*x^8+корень(x-3)*корень(x+3)*(4*x^7+6*x^6-39*x^5-45*x^4+90*x^3+64*x^2-39*x-9)+6*x^7-57*x^6-72*x^5+225*x^4+206*x^3-231*x^2-108*x+27)/(4*x^8+корень(x-3)*корень(x+3)*(4*x^7-6*x^6-39*x^5+45*x^4+90*x^3-64*x^2-39*x+9)-6*x^7-57*x^6+72*x^5+225*x^4-206*x^3-231*x^2+108*x+27)