Find all the zeros of each equation x^5-3x^4-15x^3+45x^2-16x+48=0

Zero means the roots of the problem. So,

x^5 - 3*x^4 - 15*x^3 + 45*x^2 - 16*x + 48 = 0 is the given, then factor this, the result is:

= (x + 4) * (x - 3) * (x - 4) * (x^2 + 1) = then factor this again, this will give us the roots:

= (x + 4) * (x - 3) * (x - 4) * (x + i) * (x - i)

The real roots are:-4, 3, 4

While the complex roots are - i, i.