Respuesta :
we factor by grouping
f(x)=(x³+x)+(5x^2+5)
f(x)=x(x²+1)+5(x²+1)
undistribute x²+1
f(x)=(x+5)(x²+1)
set each to zero
0=x+5
x=-5
0=x²+1
-1=x²
i=x
1 real root and 1 imaginary root
f(x)=(x³+x)+(5x^2+5)
f(x)=x(x²+1)+5(x²+1)
undistribute x²+1
f(x)=(x+5)(x²+1)
set each to zero
0=x+5
x=-5
0=x²+1
-1=x²
i=x
1 real root and 1 imaginary root