1)(3x+1)/(4x-1)+(4-7x)/(4x-1)=0
(3x+1+4-7x)/(4x-1)=0
5-4x=0 одз: x=1/4
-4x=-5
x=5/4
x=1,25
2) (2x(10x-1)-(3-x^2))/2x(3-x^2)=0
20x^2-2x-3+x^2=0 одз: x=0, x=~/3
21x^2-2x-3=0
D=4+252=256
x1=10/21 x2=-8/21
3) (x+4x+x^2+12+3x)/(4-x)(4+x)
x^2+8x+12=0 одз: x=4 x=-4
D=64-48=16
x1=-2 x2=-6