Объяснение:
a)(2a-1)/5b + a/b=(2a-1+5b)/5b=(2a+5b-1)/5b
b)3/(x²-1)-2/(x-1)=(3-2(x+1)/(x²-1)=(3-2x-1)/(x²-1)=(-2x+2)/(x²-1)= =-2(x-1)/(x²-1)=-2/(x+1)
*x²-1=(x-1)(x+1)
