a) 1/(3x-1) =(3x+1)/(3x-1)(3x+1)=(3x+1)/(9x²-1)
1/(3x+1) =(3x-1)/(3x-1)(3x+1)=(3x-1)/(9x²-1)
b) 2/(2y+y²)=2/y(y+2)=2(y-2)/y(y²-4)
4/(y²-4)=4/(y+2)(y-2)=4y/y(y²-4)
c) x/(x²-4)=x/(x+2)(x-2)=x(x+2)/(x+2)²(x-2)
2/(x²+4x+4)=2/(x+2)² =2(x-2)/(x+2)²(x-2)
1/(x+2)=(x+2)(x-2)/(x+2)²(x-2)