F(x)=(x^2-1)(x^2-9)(x^2-16)

Question

F(x)=(x^2-1)(x^2-9)(x^2-16)

Answer 1

X^2-1=0
X^2=1
X1=+1
X2=-1

X^2-9=0
X^2=9
X3=+3
X4=-3

X^2-16=0
X^2=16
X5=4
X5=-4