1).в2+4в+3-в+7+2в2=3в2+3в+10
2).х2-2х+3
если х=-2.1 ,то х*(-2.1) -2х*(-2.1)+ 3=-2.1 во 2-ой степени +4,2 +3=4,41+4.2+3=11,61
0.4^-1=6-x
(2/5)^-1=6-x
5/2=6-x
x=6-5/2
x=3.5
<span>Решите неравенство
cos^2 (x/3)-sin^2(x/3)>0,5 </span>⇔cos (2x/3)>0,5 ⇔
-arccos0,5+2πn<x<arccos0,5+2πn, n∈Z
<span>
-</span>π/3+2πn<x<π/3+2πn, n∈Z<span>
</span>
2t-(17-(t-7))=3(t-8)
2т-(17-т+7)=3т-24
2т-17+т-7=3т-24
3т-24=3т-24