<span>(х</span>²<span>-1)(х</span>²<span>+3)=(х</span>²<span>+1)</span>²<span>+х
х</span>⁴+3х²-х²=х⁴+2х²+1+х
3х²-х²-3=2х²+1+х
2х²-3=2х²+1+х
-3=1+х
-х=1+3
-х=4
х=-4
Ответ: -4.
2.4 <2b<3 2.4+3 <a+2b<4+3 5.4< a+2b<7
D=(-5)^2-4*6*1=25-24=1; x1=(5-1)/12, x2=(5+1)/12. x1=1/3, x2=1/2. 6x^2-5x+1=6*(x-1/3)*(x-1/2)=(6x-2)*(x-1/2).
-0,4x^2y×(-10 x y^2)=4(x^2)*x*y*(y^2)=4x^3*y^3=4(xy)^3