CANCELED !!!DELETED !!!
1)\((f\circ g)(x)=f(g(x))\\\\(f\circ g)(x)=f(x^2)\\\\(f\circ g)(x)=3(x^2)+3\\\\(f\circ g)(x)=3x^2+3\\\\(f\circ g)(-3)=3\cdot(-3)^2+3\\\\(f\circ g)(-3)=3\cdot9+3\\\\(f\circ g)(-3)=27+3\\\\\boxed{(f\circ g)(-3)=30}\)2)\(x^2-10=26\\\\x^2-36=0\\\\(x-6)(x+6)=0\\\\\boxed{S=\{-6,6\}}\)
