Question

Priya wants to sketch a graph of the polynomial f defined by f(x)=x^3+5x^2-8. She knows f(1)=0, so she suspects that (x-1) could be a factor of x^3+5x^2+2x-8 and writes (x^3+5x^2+2x-8)=(x-1)(?x^2+?x+?) and draws a diagram