Х^3+4х^2-21х=0x(х^2+4x-21)=0
x=0 х^2+4x-21 =0
D=100
x1=(-4+10)/2=3
x2=(-4-10)/2=-7
Ответ 0,-7,3
A) 6 <2x<span><8
21</span><3y<span><24
27</span><2x+3y<span><32
b) 21</span><xy<span><32
84</span><4xy<span><128
</span><span>
</span>
181818 : 54 - 818181 : 243 =
= 181818 : (18· 3) - 818181 : (81 ·3) =
= 181818 : 18 : 3 - 818181 : 81 : 3 =
= 10101 : 3 - 10101 : 3 = 0