Turn down for what?

Given roots are equal therefore d=0./n b b-4 a*1=0 i.e.,b^2=4a Now on substituting it we get 4a^2/a^2=4 Therefore the anser is 4

Just put $a=1,b=2$

It'll assume the form of $x^{2}+2x+1 = (x+1)^{2}$