Question

(x-3) (x²+3x+9)=x(x-8) (x+9)?????????????????

Answer 1

$(x-3) (x^2+3x+9)=x(x-8) (x+9) \ \ x^3 -27 = (x^2-8x)(x+9) \ \ x^3 -27 = x^3 + 9x^2 -8x^2 -72x \ \ x^2 -72x +27 = 0 \ \ D = (-72)^2 - 4 * 1 * 27 = 5184-108 = 5076 \ \ x1 = frac{72 + 6 sqrt{141} }{2} = 36+3 sqrt{141} \ \ x2 = frac{72 - 6 sqrt{141} }{2} = 36-3 sqrt{141}$