Question

without using a calculator, find all the roots of the equation.
x^3+x^2+4x+4=0
x^3+4x^2+x-6=0
x^4-4x^3+x^2+12x-12=0

find all the zeros of the function
y=x^4-6x^2+8
y=x^3+6x^2+x+6
g(x)=x^3-4x^2-x+22
y=x^4-x^3-5x^2-x-6