Question 1093636
From the roots, the factors are (x-4)^2*(x+4)
when x=0, y=-51.2
(x^2-8x+16)(x+4)=x^3-4x^2-16x+64
but when x=0, y=-51.2
a*(x^3-4x^2-16x+64), when x=0, 64a=-51.2.  Therefore, a=-0.8
The equation is -0.8x^3+3.2x^2+12.8x-51.2
{{{graph(300,300,-10,10,-150,100,-(0.8)(x^3-4x^2-16x+64))}}}