A+c=-b;
a+b=-c;
b+c=-a;
a)(2(a+b)+2b-3c)/(3(a+b)+4b-7c)=(-2c+2b-3c)/(4b-10c)=(2b-5c)/(2(2b-5c))=1/2;
(a+c+2b)/(a+c+8b)=(-b+2b)/(-b+8b)=b/7b=1/7;
(1/7)/(1/2)=2/7;
b)(3(a+b)+b-7c)/(4(a+b)+b-6c)=(-3c+b-7c)/(-4c+b-6c)=(b-10c)/(b-10c)=1;
(2a+(b+c))/(7a+(b+c))=(2a-a)/(7a-a)=a/6a=1/6;
1/(1/6)=6;
7х-4х-3=3х+2
3х-3=3х+2
3х-3х=2+3
0=5
Решений нет
( 7/11 ) ^ 4x - 5 = ( 11/7 ) ^ 5x - 4
( 7/11 ) ^ 4x - 5 = ( 7/11 ) ^ 4 - 5x
4x - 5 = 4 - 5x
9x = 9
X = 1
X(y-1)-((xy-x)-(y-xy))=x(y-1)-(x(y-1)-y(1-x))=x(y-1)-x(y-1)+y(1-x)=y(1-x)=y-xy