2,2х=1,5-0,18
2,2х=1,32
х=1,32:2,2
х=0,6
Воспользуемся свойствами логарифма:
1) loga(b) = 1/logb(a)
2) loga(x^n) = n*loga(x)
log5(2)*log2(125) = (1/log2(5))*log2(5^3) = 3*log2(5)/log2(5) = 3
18-8x+16<10-4x
-8x+4x<-18-16+10
-4x<-24
x>6
{3-2x≤5x-10+3x⇒8x+2x≥3+10⇒10x≥13⇒x≥1,3
{1-3x≥20x-4-21x⇒-x+3x≤1+4⇒2x≤5⇒x≤2,5
x∈[1,3;2,5]