<span>(11/8 - 1 7/11 )*2,2=-6,325</span>
X³+x²-xу²-y²=(х³+х²)-(ху²+у²)=х²(х+1)-у²(х+1)=
=(х+1)(х²-у²)=(х+1)(х-у)(х+у)
<span>x*(x-1)=56
X^2-X-56=0
D=b2-4ac=1+224=225
x1,2=1+-15/2=8,-7</span>
-7x²+2x=0
x(-7x+2)=0
a)x=0
b)-7x+2=0, -7x=-2, x=2/7
( a.b=0 ⇔ a=0 v b=0)