((((81 x)1/3+ x)1/3+ x)1/3+ x)1/3=1

Question

((((81 x)1/3+ x)1/3+ x)1/3+ x)1/3=1

Answer 1

((((81 х)1/3 +х)1/3 + х)1/3 + х)1/3 = 1
(((27х + х)1/3 +х)1/3 +х)1/3 =1
(((28х)1/3 +х)1/3 +х)1/3 =1
((28/3 * х + х)1/3 +х)1/3 =1
(31/3 *х *1/3 + х)1/3 =1
(31/9 *х + х) 1/3 = 1
40/9 *х  * 1/3 = 1
40 /27 *х = 1
40х = 27 
х = 40/27