Решите неравенство методом интервалов

1) log₁₂3 + log₁₂4 = log₁₂(3*4) = log₁₂12 = 1
2) log₇98 - log₇2 = log₇(98/2) = log₇49 = 2
3) log₂5-log₂35 + log₂56 = log₂(5/35) + log₂56 = log₂(log₂8 = 3
4) log₁/₃5 - log₁/₃5 + log₁/₃ 9 = log₁/₃9 = -2

1) lg4 + lg250= lg(4*250) = lg1000 = 3
2) log₂6 - log₂ = log₂( = log₂32 = 5
3) (log₁₂4 + log₁₂36)² = (log₁₂144)² = 2² = 4
4) lg13 - lg 130 = lg = lg = -1
5) (log₂13-log₂52)⁵ = (log₂)⁵ = (log₂)⁵ = (-2)⁵ = -32
6) (log₀.₃9 - 2log₀.₃10)⁴ = (log₀.₃9 - log₀.₃100)⁴ = (log₀.₃)⁴ = (log₀.₃0.09)⁴ = 2⁴ = 16

1) log₃x = -1
x = 3⁻¹ = 1/3
2) log₂x = -5
x = 2⁻⁵ = 1/32
3) log₃x = 2
x = 3² = 9
4) log₄x = 3
x = 4³ = 64
5) log₄x = -3
x = 4⁻³ = 1/64
6) log₇x = 0
x = 7° = 1
7) log₁/₇x = 1
x = 1/7
8) log₁/₂x = -3
x = (1/2)⁻³ = 8

1) log₂log₂log₃81 = log₂log₂4 = log₂2 = 1
2) log₂log₃log₁/₃(1/27) = log₂log₃3 = log₂1 = 0
3) log₅125 = 3 = 2
4) log₄log₃81 = log₄4 = 1

Собственная скорость лодки Х км/час, тогда скорость по течению Х+2, а скорость против течения Х-2.
Время по течению = 4/Х+2;      время против течения = 1/Х-2
Составим уравнение :
4/ (Х+2) + 1/(Х-2) =1/3
3*4(Х-2) + 3*1(Х+2) = X^2 - 4
12X-24 +3X+6 = X&2 - 4
-X^2 + 15X -14 = 0
X^2 -15X+14 = 0
D = 225 -4(14)= 225 -56 =Y169;  D = 13
X1 =(15 +13) / 2 = 14
X2 = (15-13)/2 = 1 ( не подходит по условию задачи)
ответ:  14км/час -собственная скорость моторной лодки.

3(х+1)-2(2-х)>-11
3х+3-4+2х>-11
5х-1>-11
5х>-11+1
5x>-10
x>-2