Question

(Х+4)²-х²=2х+1
х(х²-2)=х³+8

Answer 1

( X + 4)^2 - X^2 = 2X + 1 
X^2 + 8X + 16 - X^2 = 2X + 1 
8X + 16 = 2X + 1 
8X - 2X = 1 - 16 
6X = - 15
X = - 2,5 
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X * ( X^2 - 2 ) = X^3 + 8 
X^3 - 2X = X^3 + 8 
- 2X = 8 
X = - 4