Ответ:\((t^3g)^4=t^{12}g^4\).\(9t^3gx^2\cdot t^{12}g^4=9t^{3+12}g^{1+4}x^2=9t^{15}g^5x^2\).Ответ: \(9t^{15}g^5x^2\).