What expressions are equivalent to 4x-8x+12y

Which shows one way to determine the factors of  x3  +  5x2  –  6x  –  30 by grouping? x(x2  –  5)  +  6(x2  –  5)x(x2  +  5)  –  6(x2  +  5)x2(x  –  5)  +  6(x  –  5)x2(x  +  5)  –  6(x  +  5)

Use the x-intercept method to find all real solutions of the equation. x^3-10x^2+27x-18=0

Can someone answer this question? : )