# Thread: Corrected the error 4,5,6

1. ## Corrected the error 4,5,6

Corrected the error and explanation of :

4 ) x real number :
5 ) In complexe number, this equation :
have a singel resolution
6 ) x real number :

2. 4) $\sqrt{x^2(x+1)}=|x|\sqrt{x+1}$

5) $x^3=-\frac{27}{8}$
$x^3+\frac{27}{8}=0$
$(x+\frac{3}{2})(x^2-\frac{3}{2}x+\frac{9}{4})=0$
$x=-\frac{3}{2}$ or $x=\frac{3}{4}(1+i\sqrt3)$ or $x=\frac{3}{4}(1-i\sqrt3)$

6) $x=1 \implies x^2=1$
However, $x^2=1 \implies x=1$ or $x=-1$