$b)$  

$9x^3-72=0\mid +72$  

$9x^3=72\mid :9$  

$x^3=8$  

$x=2$  

 

 

 

$c)$  

$1,25x^3+10=0\mid -10$ $1,25x^3+10=0\mid -10$  

$1,25x^3=-10$  

$1\frac{1}{4}{x}^3=-10$  

$\frac{5}{4}{x}^3=-10\mid \cdot \frac{4}{5}$  

$x^3=-\frac{40}{5}$  

$x^3=-8$  

$x=-2$  

 

 

 

$d)$  

$24x^3-3=0\mid +3$  

$24x^3=3\mid :24$  

$x^3=\frac{3}{24}$  

$x^3=\frac{1}{8}$  

$x=\frac{1}{2}$  

 

 

 

$e)$  

$54x^3+16=0\mid -16$  

$54x^3=-16\mid :54$  

$x^3=-\frac{16}{54}$  

$x^3=-\frac{8}{27}$   

$x=-\frac{2}{3}$  

 

 

$f)$  

$125x^3-64=0\mid +64$  

$125x^3=64\mid :125$  

$x^3=\frac{64}{125}$  

$x=\frac{4}{5}$