16.15
log2 (x²) * log2 (x²) - 5log2(x^4) +24 =0; x>0
4 * (log2 (x))² - 5*4 log2 (x) +24 = 0
m = log2 (x)
4m² -20m +24 =0
m² -5m +6 =0
D = 25 - 24 =1
m1 = (5 +1)/2 = 3 log2(x) = 3 ----> x1 = 8
m2 = (5-1)/2 = 2 log2(x) = 2 -----> x2 =4
16.16
lgx * log2 (x) = lg2 формула перехода: log2(x) = lg(x)/lg2
lg(x)*lg(x)/lg2 =lg2
(lg(x))² = (lg2)²
lg(x) =lg2
x = 2