2х²-11х+23-х²+10х-25>0
x²-x-2>0
x1+x2=1 U x1*x2=-2⇒x1=-1 U x2=2
+ _ +
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-1 2
x∈(-≈;-1) U (2;≈)
X^2 + 5x^2 = 6x^2
6x^2*6x = 36x^3
cos2x*sin2x=(sin0+sin4x)2
1. 3//4=0.75
2. 0.75^2=9//16
3. (5//16)-(9//16)=-0.25
4. 2.4:(-0.25)=-2.4/0.25
5. 2.4/0.25=9.6
если конечно 5/16 это дробь