как решить уравнение? (х^2 - 3х) ^2 -14 + 42х +40 =0

Question

Валентина · Accepted Answer

Решение:
(х²-3х) ² -14x² + 42х + 40 = 0 
(х²-3х) ² -14x² + 42х + 40 = 0 
x^4 - 6x³ -5x² + 42x + 40 = 0 
(x+1)(x³-7x²+2x+40) = 0 
(x+1)(x+2)(x²-9x+20) = 0 
(x+1)(x+2)(x-4)(x-5) = 0 
x1=-1 
x2=-2 
x3=4 
x4=5

Anar Guliev · Answer

пропущено x² ? 
(х²-3х) ² -14x² + 42х + 40 = 0 
(х²-3х) ² -14x² + 42х + 40 = 0 
x^4 - 6x³ -5x² + 42x + 40 = 0 
(x+1)(x³-7x²+2x+40) = 0 
(x+1)(x+2)(x²-9x+20) = 0 
(x+1)(x+2)(x-4)(x-5) = 0 
x1=-1 
x2=-2 
x3=4 
x4=5