(x-3)³=(5-x)³
x³-9x²+27x-27=125-75x+15x²-x³
x³-9x²+27x-75x-15x²+x³=125+27
2x³-24x²-48x=152
2x(x²-12x-24)=152
↓ ↓
2x=152 или x²-12x-24=152
x=76 x²-12x=176
x(x-12)=176
↓ ↓
x=176 или x-12=176
x=188
Ответ:76;176;188.
18-9x-12x+4=22-21x. Ответ: 22-21x.
-2x²+7x-6<0
2x²-7x+6>0
D=49-48=1
x1=7+1/4=2
x2=(7-1)/4=3/2
2(x-2)(x-3/2)>0
x<3/2 ,и х>2
(2x-3y)y+(2y-3x)x = 2xy-3y^2+2xy - 3x^2 = 4xy - 3*(x^2+y^2) = 4*(-5) -3*(x^2+y^2) = -20-3*131 = -413<span>
xy = -5
x+y = -11
=> (x+y)^2 = 121
x^2 + 2xy+y^2 = 121
x^2+y^2 = 121-2xy = 121-2*(-5) = 121+10 = 131</span>