5х-4=х-12
<span>4х=-8 </span>
<span>х=-2 </span>
<span>у=5*(-2)-4 или -2-12 </span>
<span>у=-14</span>
-7t²(2t^17-3k)+5(4t^19-2k)=
=-14t^19+21t²k+20t^19-10k=
=6t^19+2t²k-10k
(4a³-3b)*2b-3b(9a³-4b)=
=8a³b-6b²-27a³b+12b²=
=-19a³b+6b²
7ab(8a²-b²)+8ab(b²-7a²)=
=56a³b-7ab³+8ab³-56a³b=ab³
pri a=10 ; b=-3
ab³=10*(-3)³=10*(-27)=-270
2√10 - 2√25 - 5 - 2√10 - 2 =
= - 2√25 - 7 = -10 - 7 = - 17