10:
\(=\dfrac{\left(7x-2\right)\left(x-1\right)-6x\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}\)
\(=\dfrac{7x^2-7x-2x+2-6x^2-6x}{\left(x-1\right)\left(x+1\right)}\)
\(=\dfrac{x^2-15x+2}{x^2-1}\)
9: \(\left(6\sqrt{x}-2x\right)\cdot\left(\sqrt{x}+4\right)\)
\(=6x+24\sqrt{x}-2x\sqrt{x}-8x\)
\(=-2x\sqrt{x}+24\sqrt{x}-2x\)
8: \(\left(3x\sqrt{x}-2\right)\left(-7\sqrt{x}+5\right)\)
\(=3x\sqrt{x}\cdot\left(-7\sqrt{x}\right)+3x\sqrt{x}\cdot5+2\cdot7\sqrt{x}-10\)
\(=-21x^2+15x\sqrt{x}+14\sqrt{x}-10\)
7: \(\left(8\sqrt{x}+3\right)\left(4-3\sqrt{x}\right)\)
\(=32\sqrt{x}-24x+12-9\sqrt{x}\)
\(=-24x+23\sqrt{x}+12\)
6: \(\left(2\sqrt{x}-3\right)\left(3\sqrt{x}+4\right)\)
\(=6x+8\sqrt{x}-9\sqrt{x}-12\)
\(=6x-\sqrt{x}-12\)
