1/(b-3)-6b/(b²-9)·(1/(b-2)-2/(b²-2b))=1/(b-3)-6b/(b²-9)·((b-2)/b(b-2))=
=1/(b-3)-6b/(b²-9)·1/b=1/(b-3)-6b/b(b²-9)=(b(b+3)-6b)/b(b²-9)=(b²+3b-6b)/b(b-3)(b+3)=
=b(b-3)/b(b-3)(b+3)=1/(b+3)
1) 5y = -7x + 10
y = - 0,7 x +2 x должен быть кратным 10
х = 10 у = -7 + 2 = -5
х = 20 у = -14 + 2 = -12
и т.д.
2) -11 у = -3 х -4
у = 3/11 х + 4/11= (3х + 4)/11
х= 28
у = (3·28 + 4)/11 = 88/11 =8