12*a*b^2-3*a*c=3*a(4b^2-с). x^6-16*x^2=x^2(x^4-16)=x^2*(x^2-4)*(x^2+4).
Y=√((8+2x-x²)/(x-1))
ОДЗ: (8+2x-x²)/(x-1)≥0 x-1≠0 x≠1.
8+2x-x²=-(x²-2x-8)=-(x²-4x+2x-8)=-(x*(x-4)+2*(x-4))=-(x-4)(x+2)=(4-x)(x+2). ⇒
(4-x)(x+2)/(x-1)≥0
-∞______+______-2______-______1______+______4______-______+∞
Ответ: ОДЗ: x∈(-∞;-2]U(1;4].
P = 2(a + b) = 10
S = a*b = 6
a + b = 5
a*b = 6
a = 5 - b
b(5 - b) - 6 = 0 *
* - b^2 + 5b - 6 = 0
b^2 - 5b + 6 = 0
D = 25 - 24 = 1
b1 = ( 5 + 1)/2 = 6 /2 = 3;
b2 = ( 5 - 1)/2 = 4/2 = 2;
a1 = 5 - b1 = 5 - 3 = 2
b1 = 3
a2 = 5 - b2 = 5 - 2 = 3
b2 = 2
х²y-xy²-2x²y-2xy²=-x²y-3xy²