In order to see how many real roots it has you have to see what the Δ is
So if Δ>0 then there are 2 real roots
If Δ=0 there is 1 real root
If Δ<0 no real root
And we know that:
Δ=b^2-4ac
So in the equation: Δ=b^2+4 and b^2 is always a number greater than or equal to 0 so when you add 4 to it, it is always greater than 0
So it has 2 real roots