Question

(х+1)⁴ +(х+1)²- 6 =0

Answer 1

((х+1)²)² +(х+1)²- 6 =0(х+1)²=t
t²+t-6=0
D = b2 - 4ac = 12 - 4·1·(-6) = 1 + 24 = 25
t1 = (-1 - √25):2*1 = (-1 - 5):2 = -6/2 = -3
t2 = (-1 + √25):2*1 = (-1 + 5):2 = 4/2 = 2

(х+1)²=2
х+1=+-√2
х=+-√2-1