\(F=x^2+6x-5=x^2+6x+9-14=\left(x+3\right)^2-14\)
\(G=x^2-8x-5=x^2-8x+16-21=\left(x-4\right)^2-21\)
\(H=x^2-10x+31=x^2-10x+25+6=\left(x-5\right)^2+6\)
\(K=x^2-12x+9=x^2-12x+36-27\)
\(=\left(x-6\right)^2-27\)
\(M=x^2-14x+20=x^2-14x+49-29\)
\(=\left(x-7\right)^2-29\)
\(N=x^2-16x+25=x^2-16x+64-39\)
\(=\left(x-8\right)^2-39\)
\(P=9x^2+12x+5\)
\(=9x^2+12x+4+1=\left(3x+2\right)^2+1\)
\(S=9x^2+6x+3=9x^2+6x+1+2=\left(3x+1\right)^2+2\)