✔ 最佳答案
log(x) 8 + log (8) X =4
(log8)/logx + (logx)/log8 = 4
(log8)^2 + (logx)^2 = 4(log8)(logx)
(logx)^2 - 4(log8) (logx) + (log8)^2 = 0
logx = { 4log8 +/- √[(4log8)^2 - 4(log8)^2] } / 2
logx = [ 4log8 +/- √12(log8)^2] / 2
logx = 2log8 +/- (√3)(log8)
logx = (2 + √3)log8 or (2 - √3)log8
logx = log ( 8 ^ (2 + √3) ) or log ( 8 ^ (2 - √3) )
x = 8 ^ (2 + √3) or 8 ^ (2 - √3)