А.
6y-9-3.4>4y-2.4
2y>10
y>5
б.
x≥6
Tgˇ2 x -3=0, tgˇ2 x = 3, /tg x/=V(3).
a)tg x = V(3), x= pí/6+k.pí
b)tg x = -V(3), x=2pí/2+k.pí
2.cosx-1=0, 2cosx=1, cosx=1/2
a)x=pí/3+2k.pí
b)x=5pí/3+2k.pí
k=0,1,-1,2,-2,.....
4x^4*(-8x^5)
-4x^4*8x^5
-32x^4x^5
-32x^2
(4x-9x²)/(10-x)≥0 ОДЗ: 10-x≠0 x≠10
4x-9x²≥0 x(4-9x)≥0 x≥0 x≤4/9 x∈[0;4/9]
10-x≥0 x≤10
x(4-9x)/(10-x)≥0
-∞_____-____0____+____4/9____-____10____+_____+∞
x∈[0;4/9]∨(10;+∞).