1)<span>3х+1>2(х-1)+6х
3х+1>2x-2+6x
3x+1-2x+2-6x>0
-5x>-3
x<0,6
Ответ: Х</span>∈(-∞;0.6)
2)1-А
2.-Б
3.-В
4)<span>х+1/х-1 +х+2/х+1 +х+3/1-х^2 =0.
(х+1)(х+1)+(х+2)(х-1)/(x-1)(x+1)=0
(x+2)(x-1)=0
</span>x=-2 и х=1
-13m^3+10m^2+12
--------------------------- -20
3
2^2k+5 * 3^3+k / 2^k+2 * 3^k+2 * 2^k+2 = 2^2k+5-k-2 * 3^3+k-k-2 / 2k+2 = 2^k+3 * 3^1 / 2^k+2 = 2^k+3-k-2 * 3^1 = 2^1 * 3^1 = 6