\(1,\\ a,=-10x^3+x^2-15x\\ b,=10x^2-2x^3-15x+3x^2=13x^2-2x^3-15x\\ c,=2x^2-6x-5x^2+4x-10x+8\\ =-3x^2-12x+8\\ d,=16x^2-9+4-12x+9x^2=25x^2-12x-5\\ e,=4x^2+20x+25-25-16+x^2=5x^2+20x-16\\ 2,\\ a,\Leftrightarrow x^2-3x-x^2=-6\\ \Leftrightarrow-3x=-6\Leftrightarrow x=2\\ b,\Leftrightarrow x^2-3x+2-x^2-x+12=0\\ \Leftrightarrow-4x=-14\Leftrightarrow x=\dfrac{7}{2}\\ c,\Leftrightarrow9x^2-12x+4-6-2x-9x^2=2\\ \Leftrightarrow-14x=4\Leftrightarrow x=-\dfrac{2}{7}\)
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