(a-b)³=a³-3ab(a-b)+b³
[tex]\sqrt[3]{8x+4} -\sqrt[3]{8x-4} =2\ \ \ |^3\\\\8x+4-8x+4-3\sqrt[3]{(8x-4)(8x+4)}( \sqrt[3]{8x+4} -\sqrt[3]{8x-4} )=8[/tex]
observam ca paranteza este de fapt egala cu 2
si vom avea
[tex]8-3\sqrt[3]{(8x-4)(8x+4)} \times2=8\\\\8-6\sqrt[3]{(8x-4)(8x+4)}=8\ \ \ |:2\\\\4-3\sqrt[3]{(8x-4)(8x+4)} =4\\\\3\sqrt[3]{(8x-4)(8x+4)} =0[/tex]
8x-4=0
x=[tex]\frac{1}{2}[/tex]
8x+4=0
x=-[tex]-\frac{1}{2}[/tex]
