\(a,\Leftrightarrow4\left(3x^2+7x-6\right)-3\left(4x^2-5x+1\right)=-27\\ \Leftrightarrow12x^2+28x-24-12x^2+15x-3=-27\\ \Leftrightarrow43x=0\Leftrightarrow x=0\\ b,\Leftrightarrow60x^2+35x-60x^2+15x=-100\Leftrightarrow50x=-100\Leftrightarrow x=-2\\ c,\Leftrightarrow0,6x^2-0,3x-0,6x^2-0,39x=0,138\\ \Leftrightarrow0,69x=0,138\Leftrightarrow x=0,138:0,69=0,2\\ d,\Leftrightarrow\left(x^2+3x+2\right)\left(x+5\right)-x^3-8x=27\\ \Leftrightarrow x^3+8x^2+17x+10 -x^3-8x=27\\ \Leftrightarrow8x^2+9x-17=0\Leftrightarrow\left(x-1\right)\left(8x+17\right)=0\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{17}{8}\end{matrix}\right.\)
a: Ta có: \(4\left(x+3\right)\left(3x-2\right)-3\left(x-1\right)\left(4x-1\right)=-27\)
\(\Leftrightarrow4\left(3x^2+7x-6\right)-3\left(4x^2-5x+1\right)=-27\)
\(\Leftrightarrow12x^2+28x-24-12x^2+15x-3=-27\)
\(\Leftrightarrow43x=0\)
hay x=0
b: Ta có: \(5x\left(12x+7\right)-3x\left(20x-5\right)=-100\)
\(\Leftrightarrow60x^2+35x-60x^2+15x=-100\)
\(\Leftrightarrow50x=-100\)
hay x=-2
