Question

Determinati multimea A= { x ∈ R | E(x)+F(x)=0}

E(x) = (x+1)(x-2)(x+2)
F(x)= (x+1)(x-1)(x+2)

Answer 1

E(x)=(x+1)(x-2)(x+2)

E(x)=x(1-2+2)

E(x)=x-2x+2x

E(x)=x

F(x)=(x+1)(x-1)(x+2)

F(x)=x(1-1+2)

F(x)=2x

E(x)+F(x)=0

x+2x=0

3x=0⇒x=0