А
21/(x+1)=16/(x-2)-6/x
x≠-1 x≠2 x≠0
21x(x-2)=16x(x+1)-6(x-2)(x+1)
21x²-42x-16x²-16x+6x²-12x+6x-12=0
11x²-64x-12=0
D=4096+528=4624
x1=(64-68)/22=-2/11
x2=(64+68)/22=6
б
2/y(y-3)-1/(y-3)=5/y(y-3)(y+3)
y≠0 y≠3 y≠-3
2(y+3)-y(y+3)=5
2y+6-y²-3y-5=0
y²+y-1=0
D=1+4=5
y1=(-1-√5)/2
y2=(-1+√5)/2
в
18/(2x+1)²-1/x(2x-1)=6/(2x-1)(2x+1)
x≠-1/2 x≠1/2
18x(2x-1)-(2x+1)²=6x(2x+1)
36x²-18x-4x²-4x-1-12x²-6x=0
20x²-28x-1=0
D=784+80=864
x1=(28-12√6)/40=0,7-0,3√6
x2=0,7+0,3√6