Log (a^k) b^m = m/k * log (a) b
log2 x + 2log4 x + 3log8 x + 4log16 x = 4
одз x>0
log2 x + 2log2^2 x + 3 log2^3 x + 4log2^4 x = 4
log2 x +2*1/2 log2 x + 3*1/3 log2 x + 4*1/4 log2 x=4
4log2 x = 4
log2 x = 1
x=2
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log3 x + 2log9 x + 3log27 x + 4log81 x = 8
одз x>0
log3 x + 2log3^2 x + 3 log3^3 x + 4log3^4 x = 8
log3 x +2*1/2 log3 x + 3*1/3 log3 x + 4*1/4 log3 x=8
4log3 x = 8
log3 x = 2
x=9