Đáp án+Giải thích các bước giải:
\(62.\quad 25x^2y^6 -60xy^4z^2+36y^2z^4\\=y^2(25x^2y^4-60xy^2z^2+36z^4)\\=y^2[(5xy^2)^2-2\times 5xy^2 \times 6z^2 +(6z^2)^2]\\=y^2(5xy^2 -6z^2)^2\\63.\quad \dfrac{1}{9}u^4v^6 -\dfrac{1}{3}u^3v^4 +\dfrac{1}{4}u^6v^2\\= \dfrac{1}{36}u^4v^2(4v^4 -12uv^2 +9u^2)\\= \dfrac{1}{36}u^4v^2[(2v^2)^2 -2\times 2v^2 \times 3u +(3u)^2]\\=\dfrac{1}{36}u^4v^2(2v^2 -3u)^2\\64^*\quad \dfrac{9}{16}x^{2m-2}y^2-2x^my^m+\dfrac{16}{9}x^2y^{2m-2}\\= (\dfrac{3}{4}x^{m-1}y)^2 -2 \times\dfrac{3}{4}x^{m-1}y\times \dfrac{4}{3}xy^{m-1}+(\dfrac{4}{3}xy^{m-1})^2\\=(\dfrac{3}{4}x^{m-1}y-\dfrac{4}{3}xy^{m-1})^2\\= [\dfrac{1}{12}(9x^{m-1}y-16xy^{m-1})]^2\\= \dfrac{1}{144}(9x^{m-1}y-16xy^{m-1})^2\)
