1
4/(x²-9)+(x+1)/(x-3)=1
(x-3)(x+3)≠0⇒x≠3 U x≠-3
4+(x+1)(x+3)=x²-9
4+x²+3x+x+3-x²+9=0
4x=-16
x=-4
2
2/(x-2) -1=5/(x+2)
(x+2)(x-2)≠0⇒x≠-2 U x≠2
2(x+2)-(x²-4)=5(x-2)
2x+4-x²+4-5x+10=0
x²+3x-18=0
x1+x2=-3 U x1*x2=-18
x1=-6 U x2=3
3
z/(z-1)+3/(z+1)=z/(z²-1)
(z-1)(z+1)≠0⇒z≠1 U z≠1
z(z+1)+3(z-1)=2
z²+z+3z-3-2=0
z²+4z-5=0
z1+z2=-4 U z1*z2=-5
z1=-5 U z2=1-не удов усл
4
(3x²+6x)/(x+5)=0
x+5≠0⇒x≠-5
3x²+6x=0
3x(x+2)=0
x=0 U x=-2
5
6x+1/x=5
x≠0
6x²+1-5x=0
D=25-24=1
x1=(5-1)/12=1/3
x2=(5+1)/12=1/2