Задание 6. Решите уравнение. 1) −9+x=3x−7; 2) 3−4(3x−5)=12−7x; 3) x−1−2(x+2)=−3(1−x)+8; 4) (x−4)²+(x−1)²=2x²; 5) 2x²+3x−8=5x²+4x−(−5+3x²).

1. \(-9+x=3x-7\),
   \(-2=2x\),
   \(x=-1\).
2. \(3-4(3x-5)=12-7x\),
   \(3-12x+20=12-7x\),
   \(23-12x=12-7x\),
   \(5x=11\),
   \(x=\frac{11}{5}\).
3. \(x-1-2(x+2)=-3(1-x)+8\),
   \(-x-5=3x+5\),
   \(-4x=10\),
   \(x=-\frac{5}{2}\).
4. \((x-4)^2+(x-1)^2=2x^2\),
   \(x^2-8x+16+x^2-2x+1=2x^2\),
   \(-10x+17=0\),
   \(x=\frac{17}{10}\).
5. \(2x^2+3x-8=5x^2+4x-(-5+3x^2)\),
   \(2x^2+3x-8=2x^2+4x+5\),
   \(3x-8=4x+5\),
   \(x=-13\).

Ответ: 1) −1; 2) \(\frac{11}{5}\); 3) \(-\frac{5}{2}\); 4) \(\frac{17}{10}\); 5) −13.