Question

Помогите срочно номера 3, 6, 7 и 8

Answer 1

3
(a^5-2a³+a):(1/a²-1)=a(a^4-2a²+1):(1-a²)/a²=a(1-a²)²*a²/(1-a²)=a³(1-a²)
a=3
27*(1-9)=27*(-8)=-216
6
[x(x-y)-(x-y)]/2(x-3)=(x-y)(x-3)/2(x-3)=(x-y)/2
x=y+5
(y+5-y)/2=5/2=2,5
7
x3=a,a≠0
a=4/a-3

a²+3a-4=0
a1+a2=-3 U a1*a2=-4
a1=-4⇒x³=-4⇒x=-∛4
a2=1⇒x³=1⇒x=1
-∛4*1=-∛4
8
x(x²-2x-3)/x(x-3)=(x-3)(x+1)/(x-3)=x+1
x+1=0
x=-1