1
<span>a) m(m^2-mn+n^2)-n(m^2+mn+n^2)=m³-m²n+mn²-m²n-mn²-n³=m³-2m²n-n³
b) 2c(5a-3c^2)-c(a-6c^2)+3a(a-c)</span>=10ac-6c³-ac+6c³+3a²-3ac=3a²+6ac
2
<span>a)B(a(a-b)-b(a+b))-a(b(a-b)-a(a+b))=a²</span>b-2ab²-b³+ab²-a²b+a³+a²b=a²b-ab²-b³+a³
D=9-4×1×(-18)=9+72=81, {81}=9
х1=-3+9/2=3
х2=-3-9/2= -6
Ответ: х=3; -6.
X + Y + Z = 48
Y = 2 X
Y + 8 = Z ---> 2X + 8 = Z
.......................................
X + 2X + 2X + 8 = 48
5X = 40
X = 8
Y = 16
Z = 16 + 8 = 24
ответ: числа: 8 , 16, 24