Помогите решить уравнение 4/9x³-16x=0. 0,04x³-25x=0

$\frac{4}{9 x^{3} }-16x=0 \\ \frac{4}{9 x^{3} }- \frac{16x*9x^{3}}{9x^{3}} =0 \\ \frac{4-144x^{4}}{9x^{3}} =0 \\ \frac{4(1-36x^{4})}{9x^{3}} =0 \\ \left \{ {{1-36x^{4}=0} \atop {9x^{3} \neq 0}} \right. \\ \left \{ {{36 x^{4} =1} \atop {x \neq 0}} \right. \\ \left \{ {{x = \sqrt[4]{\frac{1}{36} }} \atop {x \neq 0}} \right. \\$

0,04x³-25x=0
x(0,04x²-25)=0

x=0
0,04x²-25=0

x=0
0,04x²=25

x=0
x²=25/0,04

x=0
x²=25/0,04

x=0
x²=625

x=0
x=25