Question

Решите 1 уравнение
(x + 1)(x – 3) = x?

Answer 1

(x + 1)(x – 3) = x

x²-3x+x-3=x

x²-3x-3=0

x=$\frac{-(-3)+-\sqrt{(-3)^2-4*1*(-3)} }{2*1}$

x=$\frac{3+-\sqrt{9+12} }{2}$

x1=$\frac{3+\sqrt{21} }{2}$

x2=$\frac{3-\sqrt{21} }{2}$